03-01-2008, 08:13 AM
03-01-2008, 08:20 AM
GENETIC FLASH CHARD
03-01-2008, 08:21 AM
Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Cri-du-chat
INCIDENCE 1/50,000 live births
GENETICS Partial deletion in the short arm of chromosome 5 (5p15-)
TRANSMISSION Autosomal
CLINICAL Characteristic kitten-like cry, microcephaly, small mandible, receding chin, strabismus, profound mental retardation, sterile, true single palmar crease often found
NOTES The size of the deletion is variable, but the segment responsible for the syndrome has been narrowed down to the mid portion of 5p15 band. There does not seem to be a correlation between the size of the deletion and the clinical picture.
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Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Down syndrome
INCIDENCE 1/700 live births
GENETICS Trisomy 21
TRANSMISSION Autosomal
LAB Diagnosed prenatally by Triple test
ENZYME Blood levels of Superoxide dismutase increase at least 1.5 times in these patients
CLINICAL Maternal age effect, simian crease, generalized muscular hypotonia, poor reflexes, large fontannels, moonlike face, short nasal bridge, upturned nares, prominent epicanthic folds, hands and feet are stocky, ventricular septal defects, secondary sexual characteristics weakly manifested.
NOTES Approximately 95% of Down syndrome cases occur due to non-disjunction of chromosome 21.
of 58
Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Edwards syndrome
INCIDENCE 1/6000 live births
GENETICS Trisomy 18
TRANSMISSION Autosomal
CLINICAL Severe growth retardation, characteristic facial features, congenital heart defect (especially ventricular septal defect), omphalocele (protrusion of the bowel into the umbilical cord), diaphragmatic hernia, short neck with loose skin, narrow pelvis, fists tightly clinched, second finger overlapping the third and the fifth finger overlapping the fourth, hypoplastic nails, cyoptorchidism, hypotrophy of clitoris, hypoplasia of the labia majora also frequently observed.
NOTES Minor anomalies of diagnostic importance include small ears with unraveled helices, micrognathia, spina bifida
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Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Patau syndrome
INCIDENCE 1/4000 to 1/10,000 live births
GENETICS Trisomy 13
TRANSMISSION Autosomal
LAB Abnormal projections, blotch shaped, sessile or peduculate of the polymorph nuclei
ENZYME Esterase D is an important enzymatic marker for this disease
CLINICAL Microphthalmia, harelip usually bilateral, polydactyly, moderate microcephaly, wide saggital sutures and fontanels, and a localized scalp defect at the vertex, holoprosencephaly, palpebral fissures horizontal, nose broad and flat, low set ears, hyperconvex and narrow nails, calcaneum protruding, feet often described as 'rocker bottom' feet. Genital anomalies include cryptorchidism, bicornate uterus, hypertrophy of the clitoris, and double vagina
NOTES Malformation are extremely severe and results in high degree of lethality of the syndrome.
of 58
Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Klinefelter syndrome
INCIDENCE 1/1000 live births
GENETICS 47,XXY
TRANSMISSION Autosomal
CLINICAL Taller than average with disproportionately long arms and legs, hypogonadism, gynecomastia, predisposition to learning disabilities, weak growth of facial hair, female appearance, mostly sterile, low plasma testosterone, libido subnormal
TREATMENT Usually administered testosterone to enhance secondary male sexual characteristics like deep voice, facial hair, penile growth and libido.
NOTES 80%-90% of all patients with Klinefelter syndrome have the karyotypic abnormality 47,XXY. Structural anomalies do occur, but are very rare. Klinefelter syndromes having cells with 46 chromosomes, but structural alterations of X chromosomes, have also been described.
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Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Fragile X syndrome
INCIDENCE 1/1250 males and 1/2500 females
GENETICS Fragile site at Xq27.3
TRANSMISSION X-linked dominant
CLINICAL Mental retardation, abnormal facial appearance with large ears, and long face, hypermobile joints, macroorchidism (increased testicular volume), patients are mostly tall and thin, poor survival
NOTES On culturing cells from affected individuals in a medium deficient in folic acid, the X chromosomes sometimes exhibit breaks and gaps near the tip of the long arm. These unstained regions are called fragile sites. Fragile X syndrome shows 80% penetrance in males and 30% penetrance in females
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Cancer genetics Genetics FlashCard? FlashMode: Off Term Description
Retinoblastoma
INCIDENCE 1/20,000. Commonest in infancy, rare after age 6 exceptionally rare after age 10
GENETICS Deletion in the long arm of chromosome 13 (del 13q14.1)
TRANSMISSION Sporadic in 60% of cases, familial in 40% of cases
GENE RB1 (Tumor suppressor gene), closely linked to Esterase gene at 13q14.2
CLINICAL Amaurotic cat's eye' effect or white reflex (pupil of the affected eye has an unusual white glistening appearance on illumination). In early stages pupil looks muddy. Enlargement of tumor may turn pupil white (leucocoria). The incidence of commonest presenting symptoms in the first stage is: leucocoria 61%, strabismus 22%, and visual defect 5%.Tumor extension into the orbit results in proptosis and limitation of eye movement. On further enlargement, tumor produces a fungating mass protruding forwards accompanied with oedema of eyelids and local facial deformity.
TREATMENT Cryotherapy or photocoagulation is used for small tumors, and Radiotherapy for large tumors.
NOTES Conditions which may simulate retinoblastoma and should be considered in the differential diagnosis include larval granulomatosis, uveitis, Coats disease, angiomatosis retinae, metastatic retinal dysplasia, vitreous haemorrhage, massive retinal fibrosis, medullated nerve fibres, coloboma of choroid or optic disc, high myopia, dictyoma, retinoschisis, tuberous sclerosis, persistent tunica vasculosa lentis.
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Cancer genetics Genetics FlashCard? FlashMode: Off Term Description
Wilms' tumor
INCIDENCE 1/10,000
GENETICS Deletion in the short arm of chromosome 11 (del 11p13-p15)
TRANSMISSION Autosomal dominant
GENE WT1
CLINICAL Wilms tumor is frequently designated as WAGR syndrome. (Wilms tumor-Aniridia Genitourinary anomalies and RAS oncogene like function). The cases usually involve symptoms of all or parts of the functions implied by WAGR.
NOTES The WT is extremely complex and additional WT genes may be in chromosomes 16q, and 1p, 4p, 8p, 14p, 17p, 17q and 18q. The Wilms' tumor suppressor gene is expressed only in the maternally transmitted allele.
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Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Prader Willi Syndrome
INCIDENCE 1/25,000
GENETICS Deletion in the long arm of human chromosome 15 (del 15q11.2-q12). The same deletion when transmitted through the mother results in the Angelman syndrome
TRANSMISSION Autosomal dominant
CLINICAL Hypogonadism, obesity, short stature, small hands and feet, mental retardation, neonatal hypotonia
NOTES Recurrence risk is about 1/1000
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Biochemical disorder Genetics FlashCard? FlashMode: Off Term Description
11-ï¢-Hydroxylase deficieny
LAB Decreased serum cortisol, aldosterone, and corticosterone
ENZYME 11--ï¢-Hydroxylase
SUBSTRATE 11-Deoxycorticosterone
PATHWAY Steroid hormone synthesis
CLINICAL Increased production of deoxycorticosterone causes fluid retention , hypertension and masculinization
NOTES May also be involved in rare congenital adrenal hyperplasia
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Cri-du-chat
INCIDENCE 1/50,000 live births
GENETICS Partial deletion in the short arm of chromosome 5 (5p15-)
TRANSMISSION Autosomal
CLINICAL Characteristic kitten-like cry, microcephaly, small mandible, receding chin, strabismus, profound mental retardation, sterile, true single palmar crease often found
NOTES The size of the deletion is variable, but the segment responsible for the syndrome has been narrowed down to the mid portion of 5p15 band. There does not seem to be a correlation between the size of the deletion and the clinical picture.
of 58
Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Down syndrome
INCIDENCE 1/700 live births
GENETICS Trisomy 21
TRANSMISSION Autosomal
LAB Diagnosed prenatally by Triple test
ENZYME Blood levels of Superoxide dismutase increase at least 1.5 times in these patients
CLINICAL Maternal age effect, simian crease, generalized muscular hypotonia, poor reflexes, large fontannels, moonlike face, short nasal bridge, upturned nares, prominent epicanthic folds, hands and feet are stocky, ventricular septal defects, secondary sexual characteristics weakly manifested.
NOTES Approximately 95% of Down syndrome cases occur due to non-disjunction of chromosome 21.
of 58
Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Edwards syndrome
INCIDENCE 1/6000 live births
GENETICS Trisomy 18
TRANSMISSION Autosomal
CLINICAL Severe growth retardation, characteristic facial features, congenital heart defect (especially ventricular septal defect), omphalocele (protrusion of the bowel into the umbilical cord), diaphragmatic hernia, short neck with loose skin, narrow pelvis, fists tightly clinched, second finger overlapping the third and the fifth finger overlapping the fourth, hypoplastic nails, cyoptorchidism, hypotrophy of clitoris, hypoplasia of the labia majora also frequently observed.
NOTES Minor anomalies of diagnostic importance include small ears with unraveled helices, micrognathia, spina bifida
of 58
Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Patau syndrome
INCIDENCE 1/4000 to 1/10,000 live births
GENETICS Trisomy 13
TRANSMISSION Autosomal
LAB Abnormal projections, blotch shaped, sessile or peduculate of the polymorph nuclei
ENZYME Esterase D is an important enzymatic marker for this disease
CLINICAL Microphthalmia, harelip usually bilateral, polydactyly, moderate microcephaly, wide saggital sutures and fontanels, and a localized scalp defect at the vertex, holoprosencephaly, palpebral fissures horizontal, nose broad and flat, low set ears, hyperconvex and narrow nails, calcaneum protruding, feet often described as 'rocker bottom' feet. Genital anomalies include cryptorchidism, bicornate uterus, hypertrophy of the clitoris, and double vagina
NOTES Malformation are extremely severe and results in high degree of lethality of the syndrome.
of 58
Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Klinefelter syndrome
INCIDENCE 1/1000 live births
GENETICS 47,XXY
TRANSMISSION Autosomal
CLINICAL Taller than average with disproportionately long arms and legs, hypogonadism, gynecomastia, predisposition to learning disabilities, weak growth of facial hair, female appearance, mostly sterile, low plasma testosterone, libido subnormal
TREATMENT Usually administered testosterone to enhance secondary male sexual characteristics like deep voice, facial hair, penile growth and libido.
NOTES 80%-90% of all patients with Klinefelter syndrome have the karyotypic abnormality 47,XXY. Structural anomalies do occur, but are very rare. Klinefelter syndromes having cells with 46 chromosomes, but structural alterations of X chromosomes, have also been described.
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Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Fragile X syndrome
INCIDENCE 1/1250 males and 1/2500 females
GENETICS Fragile site at Xq27.3
TRANSMISSION X-linked dominant
CLINICAL Mental retardation, abnormal facial appearance with large ears, and long face, hypermobile joints, macroorchidism (increased testicular volume), patients are mostly tall and thin, poor survival
NOTES On culturing cells from affected individuals in a medium deficient in folic acid, the X chromosomes sometimes exhibit breaks and gaps near the tip of the long arm. These unstained regions are called fragile sites. Fragile X syndrome shows 80% penetrance in males and 30% penetrance in females
of 58
Cancer genetics Genetics FlashCard? FlashMode: Off Term Description
Retinoblastoma
INCIDENCE 1/20,000. Commonest in infancy, rare after age 6 exceptionally rare after age 10
GENETICS Deletion in the long arm of chromosome 13 (del 13q14.1)
TRANSMISSION Sporadic in 60% of cases, familial in 40% of cases
GENE RB1 (Tumor suppressor gene), closely linked to Esterase gene at 13q14.2
CLINICAL Amaurotic cat's eye' effect or white reflex (pupil of the affected eye has an unusual white glistening appearance on illumination). In early stages pupil looks muddy. Enlargement of tumor may turn pupil white (leucocoria). The incidence of commonest presenting symptoms in the first stage is: leucocoria 61%, strabismus 22%, and visual defect 5%.Tumor extension into the orbit results in proptosis and limitation of eye movement. On further enlargement, tumor produces a fungating mass protruding forwards accompanied with oedema of eyelids and local facial deformity.
TREATMENT Cryotherapy or photocoagulation is used for small tumors, and Radiotherapy for large tumors.
NOTES Conditions which may simulate retinoblastoma and should be considered in the differential diagnosis include larval granulomatosis, uveitis, Coats disease, angiomatosis retinae, metastatic retinal dysplasia, vitreous haemorrhage, massive retinal fibrosis, medullated nerve fibres, coloboma of choroid or optic disc, high myopia, dictyoma, retinoschisis, tuberous sclerosis, persistent tunica vasculosa lentis.
of 58
Cancer genetics Genetics FlashCard? FlashMode: Off Term Description
Wilms' tumor
INCIDENCE 1/10,000
GENETICS Deletion in the short arm of chromosome 11 (del 11p13-p15)
TRANSMISSION Autosomal dominant
GENE WT1
CLINICAL Wilms tumor is frequently designated as WAGR syndrome. (Wilms tumor-Aniridia Genitourinary anomalies and RAS oncogene like function). The cases usually involve symptoms of all or parts of the functions implied by WAGR.
NOTES The WT is extremely complex and additional WT genes may be in chromosomes 16q, and 1p, 4p, 8p, 14p, 17p, 17q and 18q. The Wilms' tumor suppressor gene is expressed only in the maternally transmitted allele.
of 58
Gross chromosomal disorder Genetics FlashCard? FlashMode: Off Term Description
Prader Willi Syndrome
INCIDENCE 1/25,000
GENETICS Deletion in the long arm of human chromosome 15 (del 15q11.2-q12). The same deletion when transmitted through the mother results in the Angelman syndrome
TRANSMISSION Autosomal dominant
CLINICAL Hypogonadism, obesity, short stature, small hands and feet, mental retardation, neonatal hypotonia
NOTES Recurrence risk is about 1/1000
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Biochemical disorder Genetics FlashCard? FlashMode: Off Term Description
11-ï¢-Hydroxylase deficieny
LAB Decreased serum cortisol, aldosterone, and corticosterone
ENZYME 11--ï¢-Hydroxylase
SUBSTRATE 11-Deoxycorticosterone
PATHWAY Steroid hormone synthesis
CLINICAL Increased production of deoxycorticosterone causes fluid retention , hypertension and masculinization
NOTES May also be involved in rare congenital adrenal hyperplasia
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03-01-2008, 08:21 AM
count me in ebnalfady
03-01-2008, 08:23 AM
Biochemical disorder Genetics FlashCard? FlashMode: Off Term Description
17-ï¡-hydroxylase deficiency
LAB Sex hormone and cortisol not produced, increased production of mineralocorticoid
ENZYME 17-ï¡-hydroxylase
SUBSTRATE Progesterone
PATHWAY Steroid hormone synthesis
CLINICAL Increases hypertension. Patient is phenotypically female but is unable to mature.
TREATMENT Hormone replacement therapy
NOTES May also be involved in rare congenital adrenal hyperplasia
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Biochemical disorder Genetics FlashCard? FlashMode: Off Term Description
21-ï¡-hydroxylase deficiency
LAB High ACTH level
ENZYME 21-ï¡-hydroxylase
SUBSTRATE Progesterone
PATHWAY Steroid hormone synthesis
CLINICAL Commonest form of Congenital Adrenal Hyperplasias (CAH), causes masculinization
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Metabolic disorder
Genetics FlashCard? FlashMode: Off Term Description
Acute Intermittent Porphyria
INCIDENCE 5-10 / 100,000
TRANSMISSION Autosomal dominant
LAB Increased urine levels of porphobilinogen and ï¤-aminolevulinic acid
ENZYME Deficiency in Uroporphyrinogen-1-synthetase
SUBSTRATE Porphobilinogen
PATHWAY Heme synthesis
CLINICAL Abdominal pain, polyneuropathy, hypertension, neuropsychiatric disorders
NOTES AIP condition in precipitated by drugs and alcohol
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Alkaptonuria
INCIDENCE 1/250,000
TRANSMISSION Autosomal recessive
GENE AKU (maps to human chromosome 3q21-q23
LAB Accumulation of homogentisic acid in urine
ENZYME Defective enzyme homogentisate 1,2-deoxygenase
SUBSTRATE Homogentisate
PATHWAY Amino acid metabolism
CLINICAL Degenerative arthritis, cartilage pigmentation. Due to oxidation of homogentisic acid into a dark compound alkapton, darkly staining spots are often found on the diapers of affected newborns.
NOTES This human hereditary biochemical defect was first recognised in 1859 and its genetic basis was identified by Sir Archibald Garrod in 1902.
of 58
Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Maple syrup urine disease
INCIDENCE 1/250,000
GENETICS Defective enzyme mapped to # 19q13.1-q13.2
TRANSMISSION Autosomal recessive
LAB High blood levels of leucine, isoleucine, alloleucine, alloisoleucine, valine and corresponding ketoacids during acute attacks
ENZYME Branched-chain keto acid decarboxylase (deficient)
SUBSTRATE (a) ï¡-Ketoisovalerate
(b) ï¡-Keto-ï¢-Methylvalerate
PATHWAY Amino acid metabolism (Isoleucine-Valine biosynthetic pathway)
CLINICAL Overwhelming acidosis, vomiting and CNS symptoms, mental retardation and respiratory failure (infrequent), may be fatal
TREATMENT Dietary restriction of leucine, isoleucine and valine
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Homocystinuria
INCIDENCE 1 / 200,000
GENETICS Cystathionine synthetase mapped to human chromosome 21q22
TRANSMISSION Autosomal recessive
LAB High urine levels of homocystine, methioinine and its sulphoxide. Elevated levels of homocystine and methionine also found in blood
ENZYME Cystathionine ï¢-synthetase
SUBSTRATE Homocysteine
PATHWAY Amino acid metabolism
CLINICAL Ocular, skeletal and vascular defects. Patients exhibit Osteoporosis and Marfan like appearances. Mental retardation, venous and arterial thrombosis
TREATMENT Pyridoxine, low methionine diet supplemented with cystine
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Metabolic disorder
Genetics FlashCard? FlashMode: Off Term Description
Histidinemia
INCIDENCE 1 / 20,000
GENETICS Defective enzyme mapped to chromosome 12q22-q23
TRANSMISSION Autosomal recessive
LAB Elevated blood levels of histidine and alanine.
Excess urine levels of imidazole, pyruvic acid and other histidine metabolites
ENZYME Histidase (deficient)
SUBSTRATE Histidine
PATHWAY Amino acid metabolism
CLINICAL Mental retardation or speech defects common
TREATMENT Dietary restriction of histidine
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Fabry disease
TRANSMISSION X-linked recessive
LAB Accumulation of trihexosylceramide and digalactosylceramide in body tissues
ENZYME Trihexosylceramide ï¡-glycosidase (deficient)
SUBSTRATE Galactosylgalactosyl-glucosyl ceramide (Gal-Gal-Glc-Cer)
PATHWAY Glycolipid metabolism
CLINICAL Hemizygous males have skin lesions, opacity of the eye, periodic fevers, burning sensation and pain in lower extremities, angiokeratoma on buttocks and around navel, edema due to kidney malfunction. Heterozygous females have much milder symptoms. Frequently leads to kidney and heart failure.
TREATMENT Renal transplantation has been employed as a rational mode of intervention. Attempts have also been made to correct the condition by retroviral vectors with ï¡-glycosidase A expression
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Phenylketonuria
INCIDENCE 1/10,000
GENETICS Mapped to human chromosome 12q24.1
TRANSMISSION Autosomal recessive
GENE PAH gene
LAB High blood and urine levels of phenylalanine
ENZYME Phenylalanine hydroxylase (deficient)
SUBSTRATE L-Phenylalanine
PATHWAY Amino acid metabolism
CLINICAL Mental retardation, seizures, eczema
TREATMENT Dietary restriction of phenylalanine at an early stage of the disease can prevent the occurrence of mental retardation
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Tay-Sachs disease
INCIDENCE More prevalent in Ashkenazi Jews (1/2500 to 1/5000). In general its frequency of occurrence is 1/1,000,000
GENETICS Hexosaminidase A gene mapped to chromosome 15q 23-q24
TRANSMISSION Autosomal recessive
ENZYME Hexosaminidase A (deficient)
SUBSTRATE N-acetylneuraminic acid (NANA)
PATHWAY Glycolipid metabolism
CLINICAL Mental retardation, blindness, cherry red macula, muscular weakness, seizures, fatal
NOTES Also known as Type I GM2 - gangliosidosis. Sandoff disease is Type II GM2 gangliosidosis
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17-ï¡-hydroxylase deficiency
LAB Sex hormone and cortisol not produced, increased production of mineralocorticoid
ENZYME 17-ï¡-hydroxylase
SUBSTRATE Progesterone
PATHWAY Steroid hormone synthesis
CLINICAL Increases hypertension. Patient is phenotypically female but is unable to mature.
TREATMENT Hormone replacement therapy
NOTES May also be involved in rare congenital adrenal hyperplasia
of 58
Biochemical disorder Genetics FlashCard? FlashMode: Off Term Description
21-ï¡-hydroxylase deficiency
LAB High ACTH level
ENZYME 21-ï¡-hydroxylase
SUBSTRATE Progesterone
PATHWAY Steroid hormone synthesis
CLINICAL Commonest form of Congenital Adrenal Hyperplasias (CAH), causes masculinization
of 58
Metabolic disorder
Genetics FlashCard? FlashMode: Off Term Description
Acute Intermittent Porphyria
INCIDENCE 5-10 / 100,000
TRANSMISSION Autosomal dominant
LAB Increased urine levels of porphobilinogen and ï¤-aminolevulinic acid
ENZYME Deficiency in Uroporphyrinogen-1-synthetase
SUBSTRATE Porphobilinogen
PATHWAY Heme synthesis
CLINICAL Abdominal pain, polyneuropathy, hypertension, neuropsychiatric disorders
NOTES AIP condition in precipitated by drugs and alcohol
of 58
Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Alkaptonuria
INCIDENCE 1/250,000
TRANSMISSION Autosomal recessive
GENE AKU (maps to human chromosome 3q21-q23
LAB Accumulation of homogentisic acid in urine
ENZYME Defective enzyme homogentisate 1,2-deoxygenase
SUBSTRATE Homogentisate
PATHWAY Amino acid metabolism
CLINICAL Degenerative arthritis, cartilage pigmentation. Due to oxidation of homogentisic acid into a dark compound alkapton, darkly staining spots are often found on the diapers of affected newborns.
NOTES This human hereditary biochemical defect was first recognised in 1859 and its genetic basis was identified by Sir Archibald Garrod in 1902.
of 58
Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Maple syrup urine disease
INCIDENCE 1/250,000
GENETICS Defective enzyme mapped to # 19q13.1-q13.2
TRANSMISSION Autosomal recessive
LAB High blood levels of leucine, isoleucine, alloleucine, alloisoleucine, valine and corresponding ketoacids during acute attacks
ENZYME Branched-chain keto acid decarboxylase (deficient)
SUBSTRATE (a) ï¡-Ketoisovalerate
(b) ï¡-Keto-ï¢-Methylvalerate
PATHWAY Amino acid metabolism (Isoleucine-Valine biosynthetic pathway)
CLINICAL Overwhelming acidosis, vomiting and CNS symptoms, mental retardation and respiratory failure (infrequent), may be fatal
TREATMENT Dietary restriction of leucine, isoleucine and valine
of 58
Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Homocystinuria
INCIDENCE 1 / 200,000
GENETICS Cystathionine synthetase mapped to human chromosome 21q22
TRANSMISSION Autosomal recessive
LAB High urine levels of homocystine, methioinine and its sulphoxide. Elevated levels of homocystine and methionine also found in blood
ENZYME Cystathionine ï¢-synthetase
SUBSTRATE Homocysteine
PATHWAY Amino acid metabolism
CLINICAL Ocular, skeletal and vascular defects. Patients exhibit Osteoporosis and Marfan like appearances. Mental retardation, venous and arterial thrombosis
TREATMENT Pyridoxine, low methionine diet supplemented with cystine
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Metabolic disorder
Genetics FlashCard? FlashMode: Off Term Description
Histidinemia
INCIDENCE 1 / 20,000
GENETICS Defective enzyme mapped to chromosome 12q22-q23
TRANSMISSION Autosomal recessive
LAB Elevated blood levels of histidine and alanine.
Excess urine levels of imidazole, pyruvic acid and other histidine metabolites
ENZYME Histidase (deficient)
SUBSTRATE Histidine
PATHWAY Amino acid metabolism
CLINICAL Mental retardation or speech defects common
TREATMENT Dietary restriction of histidine
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Fabry disease
TRANSMISSION X-linked recessive
LAB Accumulation of trihexosylceramide and digalactosylceramide in body tissues
ENZYME Trihexosylceramide ï¡-glycosidase (deficient)
SUBSTRATE Galactosylgalactosyl-glucosyl ceramide (Gal-Gal-Glc-Cer)
PATHWAY Glycolipid metabolism
CLINICAL Hemizygous males have skin lesions, opacity of the eye, periodic fevers, burning sensation and pain in lower extremities, angiokeratoma on buttocks and around navel, edema due to kidney malfunction. Heterozygous females have much milder symptoms. Frequently leads to kidney and heart failure.
TREATMENT Renal transplantation has been employed as a rational mode of intervention. Attempts have also been made to correct the condition by retroviral vectors with ï¡-glycosidase A expression
of 58
Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Phenylketonuria
INCIDENCE 1/10,000
GENETICS Mapped to human chromosome 12q24.1
TRANSMISSION Autosomal recessive
GENE PAH gene
LAB High blood and urine levels of phenylalanine
ENZYME Phenylalanine hydroxylase (deficient)
SUBSTRATE L-Phenylalanine
PATHWAY Amino acid metabolism
CLINICAL Mental retardation, seizures, eczema
TREATMENT Dietary restriction of phenylalanine at an early stage of the disease can prevent the occurrence of mental retardation
of 58
Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Tay-Sachs disease
INCIDENCE More prevalent in Ashkenazi Jews (1/2500 to 1/5000). In general its frequency of occurrence is 1/1,000,000
GENETICS Hexosaminidase A gene mapped to chromosome 15q 23-q24
TRANSMISSION Autosomal recessive
ENZYME Hexosaminidase A (deficient)
SUBSTRATE N-acetylneuraminic acid (NANA)
PATHWAY Glycolipid metabolism
CLINICAL Mental retardation, blindness, cherry red macula, muscular weakness, seizures, fatal
NOTES Also known as Type I GM2 - gangliosidosis. Sandoff disease is Type II GM2 gangliosidosis
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03-01-2008, 08:25 AM
Lipid storage disorder Genetics FlashCard? FlashMode: Off Term Description
Gaucher's disease
GENETICS Linked to human chromosomal locus 1q21
TRANSMISSION Autosomal recessive
GENE Glucocerebrosidase gene
ENZYME Glucosylceramide ï¢-glucosidase
SUBSTRATE Glucosyl Ceramide (Glc-Cer)
PATHWAY Glycolipid metabolism
CLINICAL Liver and spleen enlargement, Osteoporosis, mental retardation in infantile form, frequently fatal
TREATMENT Enzyme replacement therapy
NOTES Gaucher disease exists in three forms. Type I (Adult, Chronic nonneuropathic), Type II (Infantile, Acute Neuropathic) and Type III forms. Prenatal diagnosis is feasible by the use of RFLP and enzyme assays
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Lipid storage disorder Genetics FlashCard? FlashMode: Off Term Description
Krabbe's disease
TRANSMISSION Autosomal recessive
LAB Multinucelated or globoid cells in the brain tissue, elevated CSF protein
ENZYME Galactosylceramide-ï¢-galactosidase
SUBSTRATE Galactose-Ceramide
PATHWAY Glycolipid metabolism
CLINICAL Progressive psychomotor retardation, spastic quadriparesis, hypertonicity, hyperthermia,
NOTES A number of forms are recognized, differing largely in age at onset and severity of symptoms. The term Globoid cell leucodystrophy has been synonymous with Krabbe disease.
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Lipid storage disorder Genetics FlashCard? FlashMode: Off Term Description
Niemann-Pick disease
TRANSMISSION Autosomal recessive
ENZYME Sphingomyelinase (deficient)
SUBSTRATE Sphinogomyelin (Phosphorylcholine-Ceramide)
PATHWAY Glycolipid metabolism
CLINICAL Enlarged liver and spleen, mental retardation, fatal early in life. Type I is the acute form, representing about 80% of sphingomyelin lipidosis cases. Death occurs in early infancy. Type II is the chronic form. Patients exhibit prolonged survival. Types III and IV are clinically similar, and there is no compelling pathological or biochemical reason to separate them.
NOTES Prenatal diagnosis is possible for type I and type II diseases.
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Glycogen storage disorder Genetics FlashCard? FlashMode: Off Term Description
Von Gierke's disease
TRANSMISSION Autosomal recessive
LAB fasting hypoglycemia - severe, increased lactic acid, uric acid and triglycerides in the blood
ENZYME Glucose-6-phosphatase
SUBSTRATE Glucose 6-phosphate
PATHWAY Glycogen metabolism
CLINICAL Liver enlargement, Also affects kidney and intestine
NOTES Also known as Type I glycogen storage disease
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Glycogen storage disorder Genetics FlashCard? FlashMode: Off Term Description
McArdle's syndrome
GENETICS Consanguinity may increase the incidence of disorder
TRANSMISSION Mostly autosomal recessive, rarely autosomal dominant
LAB Excess muscle glycogen on PAS stain. Histochemical stain for muscle phosphorylase is negative
ENZYME Glycogen phosphorylase (deficient)
SUBSTRATE Glycogen
PATHWAY Glycogen metabolism
CLINICAL The main feature of McArdle syndrome is the presence of cramps on exertion, which is sometimes accompanied by myoglobinuria. The diagnosis is suggested by a positive ischaemic exercise test which shows that muscle cannot produce lactate.
NOTES See Von Gierke's and Pompe's disease
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Glycogen storage disorder Genetics FlashCard? FlashMode: Off Term Description
Pompe's disease
GENETICS Mapped to chromosome 17
TRANSMISSION Autosomal recessive
LAB Excessive glycogen levels found in abnormal vacuoles in cytosol
ENZYME Lysosomal ï¡ 1,4-glucosidase (Acid maltase) (deficient)
PATHWAY Glycogen metabolism
CLINICAL Patients present with symptoms of weakness and respiratory difficulties in the first few months of life and usually evolves to death due to cardiac failure within one year. In addition, skin pallor, tongue and liver enlargement are often observed in these patients.
NOTES The term Glycogenoses Type-II a has been used synonymously with this condition. Prenatal diagnosis has been attempted on cultured amniotic cells. See McArdle's syndrome and Von Gierke's disease
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Hurler's syndrome
GENETICS Mapped to 22 pter-q11
TRANSMISSION Autosomal recessive
ENZYME ï¡-L-iduronidase
PATHWAY Glycosaminoglycans metabolism
CLINICAL Combinations of progressive mental degeneration with peculiar 'Hurler phenotype', which consists of gross facial features, enlarged and deformed skull, small stature, corneal opacities, hepatosplenomegaly, valvular heart defects, thick skin, joint contractures and hernias.
TREATMENT No causal therapy is available
NOTES Hurler's syndrome is synonymous with Mucopolysaccharidosis I. Compare this condition with Hunter's syndrome.
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Hunter's syndrome
GENETICS Mapped to Xq27-q28
TRANSMISSION X-linked recessive
ENZYME Iduronate sulfatase (deficient)
PATHWAY Glycosaminoglycans metabolism
CLINICAL Presents in two forms: Acute and Mild. The clinical features are very similar to Mucopolysaccharidosis I, except that symptoms are somewhat milder and clouding of the cornea is lacking. Dwarfism, distortion face, enlargement of the liver and spleen, deafness and excretion of chondroitin- and heparitin sulfate in the urine are additional characteristics.
TREATMENT Bone marrow transplantation has been attempted but with uncertain results. Symptomatic measures are indicated as in other mucopolysaccharidoses.
NOTES Hunter's syndrome is synonymous with Mucopolysaccharidosis II.See Hurler's syndrome
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Porphyria Cutanea Tarda
TRANSMISSION Type I : sporadic
Type II: familial. Familial : Autosomal dominant
LAB Increased porphyrins in the liver, plasma, urine and stool. Urinary porphyrins consist mostly of uroporphyrin and 7-carboxylate porphyrin, with lesser amounts of coproporphyrin, and 5- and 6- carboxylate prophyrins
ENZYME Type I: URO-decarboxylase activity decreased in liver cells
Type II: Half-normal URO-decarboxylase activity is present systemically
PATHWAY Heme synthesis
CLINICAL Cutaneous photosenstivity is the major clinical feature of both type I and type II PCT. Skin lesions can become infected, especially when severe and recurrent. Patients with PCT often have a history of alcohol abuse. In addition, liver damage, excess iron and estrogen intake are most important contributing factors.
NOTES Patients with PCT are at an increased risk of developing hepatocellular carcinoma.
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Lesch-Nyhan syndrome
GENETICS Mapped to X chromosome
TRANSMISSION X-linked recessive
LAB High urine levels of uric acid
ENZYME Hypoxanthine-guanine phosphoribosyltransferase (HPRT)
SUBSTRATE a) Hypoxanthine
b) Guanine
PATHWAY Purine metabolism
CLINICAL Males mostly affected. Patients present with choreoathetosis, spasticity, mild mental retardation, 'cerebral palsy' and COMPULSIVE SELF-MUTILATION manifested by biting away lips, tongue and finger tips.
TREATMENT General measures: Avoidance of dehydration, assurance of high fluid intake and nutrition. Therapeutic treatment: Diazepam, Hydroxytryptophan have been used with mixed success.
NOTES Prenatal diagnosis possible. Index cases can be readily detected by demonstrating high ratio of uric acid to creatinine in morning urine samples, which further leads to identification of heterozygous females among relatives of an index case.
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03-01-2008, 08:26 AM
Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Gout
TRANSMISSION Autosomal recessive or X-linked. However, autosomal dominant and polygenic forms are also known
LAB Serum urate level > 6 mg / 100 mL
High uric acid levels in urine samples. Presence of monosodium urate crystals in joint fluid
ENZYME Deficiency of glucose - 6 - phosphatase (Autosomal recessive gout)
Deficiency of HGPRT (X-linked gout)
PATHWAY Purine metabolism
CLINICAL Initially asymptomatic. The first signs are pain in the great toe which may spread to other parts of foot and also to the wrists and other body parts. At later stages joints and kidney may become permanently injured.
TREATMENT Rest, elevation of affected joint, administration of analgesics including narcotics, excessive fluid intake. The acute attack responds readily to colchicine given at a dose of 0.5 mg every hour to the point of nausea, vomiting or diarrhoea. Patients also respond to indomethacin and a wide variety of newer anti-inflammatory drugs.
NOTES Can also be caused by increased levels of PRPP. Low protein diet prevents on the onset of gout.
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
Orotic aciduria
GENETICS Mapped to 3q13
LAB On cooling the urine, crystalline deposits of orotic acid form along the wall of the container
ENZYME a) Orotate phosphoribosyltransferase (low activity/absence)
b) Orotidine phosphate decarboxylase (low activity/absence)
SUBSTRATE a) Orotate (for Orotate phosphoribosyltransferase enzyme)
b) Orotidine 5'-monophosphate (OMP) (for OMP decarboxylase enzyme)
PATHWAY Pyrimidine metabolism
CLINICAL Initially normal at birth. Patients may develop severe megaloblastic anemia in the first year of life, with an accompanying retardation of physical and mental development
TREATMENT Fat rich diet in uridine results in improvement of the anemia and decreased excretion of orotate
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Lactose Intolerance
INCIDENCE Exists in 90% of adult Africans, Asians and South Americans.
ENZYME ï¢-galactosidase
SUBSTRATE Lactose
PATHWAY Lactose metabolism
CLINICAL Three types
a) Transient or congenital deficiency
b) Deficiency due to surgical removal of part of small intestine
c) Deficiency due to mucosal cell damage
May be completely asymptomatic. However, some complain of colicky pain, abdominal distention, increased flatus and diarrhoea after ingesting milk or milk products.
TREATMENT Dietary exclusion of lactose
NOTES Lactose intolerance aggravates bowel symptoms of diseases such as ulcerative colitis.
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Hematological disorder Genetics FlashCard? FlashMode: Off Term Description
Sickle cell anemia
INCIDENCE 1/500 (American Black population)
GENETICS ï¢-globin gene located at 11p15. Heterozygosity causes sickle cell trait. In the classical form the hemoglobin S, a glutamine reside of the normal ï¢ chain (hemoglobin A) is replace by a valine residue. In the Hemoglobin C, at the same position a lysine replacement occurs, and this condition causes less severe clinical symptoms.
TRANSMISSION Autosomal recessive
GENE ï¢-globin
CLINICAL Complications may arise by poor blood circulation.
TREATMENT In future correction of the defective allele is possible by transduction of the defective cells with retroviral or adenoviral vectors that can deliver the normal gene to the hematopoietic stem cells.
NOTES Sickle cell trait provides the patients immunity to Plasmodium falciparum malaria. The absence of Duffy antigen on the RBCs provides immunity to Plasmodium vivax malaria. Also known as Hemglobin S disease
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Hereditary Spherocytosis
INCIDENCE 1 / 5000 in Northern Europeans, common among Caucasians
GENETICS Basic defect involves : ankyrin-1 and ï¢-spectrin (14q22-q23)
TRANSMISSION Autosomal dominant. May also be autosomal recessive
GENE Ankyrin-1 and ï¢-spectrin genes
LAB Anemia, reticulocytosis, hyperbilirubinemia, presence of spherocytes in the peripheral smear. Diagnostically most important test: Measurement of osmotic fragility
CLINICAL Neonatal hyperbilirubinemia and exacerbations of anemia due to hemolytic or aplastic crisis associated with infections. Gallstones may develop in some patients.
NOTES The absence of the protein spectrin from the RBC membrane framework is responsible for the loss of the characteristics of biconcave shape of RBC
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Connective tissue disorder Genetics FlashCard? FlashMode: Off Term Description
Oosteogenesis imperfecta
INCIDENCE 1/5000 to 1/10,000
GENETICS Type I linked to chromosome 17
TRANSMISSION Autosomal recessive or autosomal dominant
GENE COLIA 1 and COLIA 2 (Type I collagen genes)
LAB Cultured skin fibroblasts show abnormal collagen structure
CLINICAL Severe osteoporosis, multiple fractures in infancy and childhood. Blue sclerae, abnormal dentition. The condition exists in Type I, Type II , Type III and Type IV forms.
TREATMENT No specific treatment. Biphosphate pamidronate has been found to reduce fracture rates in affected children.HRT therapy is indicated to prevent post-menopausal bone loss in women.
NOTES Also known as Brittle bone syndrome
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Connective tissue disorder
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San Fillipo disease (Types A-D)
ENZYME a) Heparan sulfamidase (deficient)
b) N-Acetylglucosaminidase (deficient)
c) N-Acetyltransferase (deficient)
d) N-Acetylglucosamine (deficient)
SUBSTRATE a) GlcN-GlcUA-GlcNAc-GlcUA... (For Heparan sulfamidase enzyme)
b) GlcN-GlcUA-GlcNAc-GlcUA... (For N-Acetylglucosaminidase enzyme)
c) GlcNAc-GlcUA-GlcNAc-GlcUA... (For N-Acetyltransferase enzyme)
d) GlcNAc-GlcUA... (For N-Acetylglucosamine enzyme)
PATHWAY Glycosaminoglycan
CLINICAL Severe nervous system disorders, mental retardation
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Cancer genetics
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Familial Adenomatous Polyposis
GENETICS Deletion (5q21-q22)
GENE APC (Tumor suppressor gene)
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Breast cancer
GENETICS Deletion (16q)
GENE CMAR/CAR (Tumor suppressor genes)
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Colon carcinoma
GENETICS Deletion (18q21)
GENE DCC (Tumor suppressor gene)
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03-01-2008, 08:29 AM
Cancer genetics
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Neurofibromatosis type 1
GENETICS Deletion (17q11.2)
GENE NF1 (Tumor suppressor gene)
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Neurofibromatosis type 2
GENETICS Deletion (22q11)
GENE NF2 (Tumor suppressor gene)
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Cancer genetics
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Melanoma
GENETICS Deletion (9p21)
GENE MTS1/MTS2/CDK41 (Tumor suppressor genes)
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Chronic Myeloid Leukemia
GENETICS Translocation (9;22)(q34;q11)
Translocation (16;21) (p11;q22)
GENE Oncogenes: ABL (9q34.1), BCR (22q11), ERG (21q22.3), TLS/FUS (16p11)
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Non-Hodgkin's lymphoma
GENETICS Translocation (2;5) (p23;q35)
Translocation (14;18) (q32;q21)
Translocation (3;14) (q27;q32)
Translocation (3;22) (q27;q11)
GENE Oncogenes: ALK (2p23), NPM (5q35), BCL2 (18q21.3), BCL6 (3q27)
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Acute Myeloid leukemia
GENETICS Translocation (8;21) (q22;q22)
Translocation (6;9) (p23;q34)
Inversion (16) (p13;q22)
GENE Oncogenes: AML1 (21q22), ETO (8q22), MTG8 (8), CAN (6p23), DEK (9q34), SET
(9q34), CBFB (16q22), MYH11 (16p13.12-p13.13)
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B-cell lymphoma
GENETICS Translocation (11;14) (q13;q32)
GENE Oncogenes: BCL1 (11q13.3), IgH (14q32)
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Ewing's sarcoma
GENETICS Translocation (22;21) (q12;q22)
Translocation (11;22) (q24;q12)
GENE Oncogenes: ERG (21q22.3), EWS (22q12), FL11 (11q24)
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Acute Lymphoblastic Leukemia
GENETICS Translocation (8;14)q24;q32)
Translocation (14;18) (q32;q21)
Translocation (4;11) (q21;q23)
GENE Oncogenes: MYC (8q24), BCL2 (18q21.3), MLL / ALL1 / HRX (11q23)
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Burkitt's lymphoma
GENETICS Translocation (8;14) (q24;q32)
Translocation (8;22) (q24;q11)
Translocation (2;8) (p12;q24)
GENE Oncogenes: MYC (8q24), IgH (14q32), Igï¬ (22q11), Igï« (2p12)
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03-01-2008, 08:31 AM
Cancer genetics
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Neurofibromatosis type 1
GENETICS Deletion (17q11.2)
GENE NF1 (Tumor suppressor gene)
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Neurofibromatosis type 2
GENETICS Deletion (22q11)
GENE NF2 (Tumor suppressor gene)
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Melanoma
GENETICS Deletion (9p21)
GENE MTS1/MTS2/CDK41 (Tumor suppressor genes)
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Chronic Myeloid Leukemia
GENETICS Translocation (9;22)(q34;q11)
Translocation (16;21) (p11;q22)
GENE Oncogenes: ABL (9q34.1), BCR (22q11), ERG (21q22.3), TLS/FUS (16p11)
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Non-Hodgkin's lymphoma
GENETICS Translocation (2;5) (p23;q35)
Translocation (14;18) (q32;q21)
Translocation (3;14) (q27;q32)
Translocation (3;22) (q27;q11)
GENE Oncogenes: ALK (2p23), NPM (5q35), BCL2 (18q21.3), BCL6 (3q27)
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Acute Myeloid leukemia
GENETICS Translocation (8;21) (q22;q22)
Translocation (6;9) (p23;q34)
Inversion (16) (p13;q22)
GENE Oncogenes: AML1 (21q22), ETO (8q22), MTG8 (8), CAN (6p23), DEK (9q34), SET
(9q34), CBFB (16q22), MYH11 (16p13.12-p13.13)
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B-cell lymphoma
GENETICS Translocation (11;14) (q13;q32)
GENE Oncogenes: BCL1 (11q13.3), IgH (14q32)
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Ewing's sarcoma
GENETICS Translocation (22;21) (q12;q22)
Translocation (11;22) (q24;q12)
GENE Oncogenes: ERG (21q22.3), EWS (22q12), FL11 (11q24)
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Acute Lymphoblastic Leukemia
GENETICS Translocation (8;14)q24;q32)
Translocation (14;18) (q32;q21)
Translocation (4;11) (q21;q23)
GENE Oncogenes: MYC (8q24), BCL2 (18q21.3), MLL / ALL1 / HRX (11q23)
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Burkitt's lymphoma
GENETICS Translocation (8;14) (q24;q32)
Translocation (8;22) (q24;q11)
Translocation (2;8) (p12;q24)
GENE Oncogenes: MYC (8q24), IgH (14q32), Igï¬ (22q11), Igï« (2p12)
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Alveolar Rhabdomyosarcoma
GENETICS Translocation (2;13) (q35;q14)
Translocation (1;13) (p36;q14)
GENE PAX3 (2q35), FKHR/ALV (13q14), PAX7 (1p36)
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Chromosomal susceptibility disorder Genetics FlashCard? FlashMode: Off Term Description
Xeroderma pigmentosum
TRANSMISSION Autosomal recessive
ENZYME DNA repair endonuclease (Deficient)
CLINICAL Abnormalities of pigmentation on exposed areas of skin, produced by sunlight, and numerous malignancies in the same area of skin.
TREATMENT Prevention of exposure to sunlight. No effective treatment available
NOTES Defective DNA repair mechanism is unable to remove Thymine dimers from the damaged DNA of cells exposed to ultraviolet component of sunlight.
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Ataxia telengiectasia
INCIDENCE 25 / 1,000,000 (occurs in higher frequency among Moroccan Jews)
GENETICS Chromosomal instability syndrome. Mostly affects chromosomes 2,7,11,12,14. Major locus at 11q22-q23.
TRANSMISSION Autosomal recessive
GENE ATM gene
LAB Cultured cells of AT patients are highly sensitive to X-ray and UV damage
ENZYME DNA dependent protein kinase (Defective)
CLINICAL Poor coordination of muscles, reduced immunity
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ï¢-Thalassemia
GENETICS Deletion of one or more ï¢-globin genes (chromosome 11p)
CLINICAL Anemia, susceptibility to infections, bone deformations, enlargement of the liver and spleen, iron deposits, delayed sexual development may appear a few months after birth
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ï¡-Thalassemia
GENETICS mapped to 16p13
LAB Mild microcytosis of peripheral blood RBCs with decreased Hb content. Peripheral blood smear reveals poikilocytosis and polychromasia.
CLINICAL Accumulation of fluids in the body of the fetus, severe anemia resulting in prenatal death. Splenomegaly and occasionally hepatomegaly are found.
NOTES ï¡-Thalassemia is synonymous with Thalassemia major
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Hemophilia A
INCIDENCE 1/10,000
GENETICS Mapped to Xq28
TRANSMISSION X-linked recessive. Generally expressed in males
GENE Factor VIII gene
LAB Increased bleeding time and frequency. Factor VIII C: less than 0.02 IU/ml (severe hemophilia), 0.02-0.05 IU/ml (moderate hemophilia), 0.05 IU/ml (mild hemophilia)
CLINICAL Common complications due to recurrent bleeds: Chronic arthropathy, muscle fibrosis, pseudotumors, Entrapment neuropathies
Common complications due to factor VIII concentrates: HIV infection, AIDS, Allergic reaction to factor VIII infusions, depressed cell mediated immunity. Chronic liver disease
TREATMENT Fresh frozen plasma and Factor VIII supplementation
NOTES The most famous case of hemophilia involved the descendents of Queen Victoria of England.
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Hematological disorder
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Christmas disease
INCIDENCE 1/50,000
GENETICS Mapped to Xq26-q27
TRANSMISSION X-linked recessive. Generally expressed in males.
LAB Factor IX levels are deficient
CLINICAL Identical to Hemophilia A
TREATMENT Fresh frozen plasma and Factor IX supplementation
NOTES Synonymous with "Hemophilia B"
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Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description
ï¡-1 Anti trypsin deficiency
ENZYME ï¡-1 Anti Trypsin
CLINICAL Due to excessive protease action damage of normal tissues, such as lung and liver can result in emphysema, neonatal respiratory distress syndrome, impaired ventilation, predisposition to serious respiratory infections, cirrhosis and hepatitis (in severe cases with homozygous ZZ genotype)
NOTES Deficiency of ï¡-1 AT permits neutrophil elastase to destroy lung. Smokers with ï¡-1 AT deficiency have a considerably elevated rate of lung destruction and poorer survival rate than do nonsmokers with the deficiency
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03-01-2008, 08:46 AM
. Von Gierke's disease is a glycogen storage disease caused by a deficiency
of glucose-6-phosphatase. It typically presents with neonatal hypoglycemia, hyperlipidemia, lactic
acidosis, and ketosis. Failure to thrive is common in early life; convulsions may occur due to
profound hypoglycemia. The glycogen accumulation in von Gierke's disease occurs primarily in the
liver and kidneys, accounting for the enlargement of these organs. Gout may develop later because of
the derangement of glucose metabolism.
of glucose-6-phosphatase. It typically presents with neonatal hypoglycemia, hyperlipidemia, lactic
acidosis, and ketosis. Failure to thrive is common in early life; convulsions may occur due to
profound hypoglycemia. The glycogen accumulation in von Gierke's disease occurs primarily in the
liver and kidneys, accounting for the enlargement of these organs. Gout may develop later because of
the derangement of glucose metabolism.