03-01-2008, 08:13 AM
HERE'S CONCEPTS
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bio..team concepts - ebnalfady
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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. 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. of 58 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 of 58 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 of 58
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 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 of 58 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 of 58 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 of 58
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 of 58 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. of 58 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. of 58 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 of 58 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 of 58 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 of 58 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. of 58 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 of 58 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. of 58 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. of 58
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. of 58 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 of 58 Metabolic disorder Genetics FlashCard? FlashMode: Off Term Description 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. of 58 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 of 58 Hematological disorder Genetics FlashCard? FlashMode: Off Term Description 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 of 58 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 of 58 Connective tissue disorder Genetics FlashCard? FlashMode: Off Term Description 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 of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Familial Adenomatous Polyposis GENETICS Deletion (5q21-q22) GENE APC (Tumor suppressor gene) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Breast cancer GENETICS Deletion (16q) GENE CMAR/CAR (Tumor suppressor genes) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Colon carcinoma GENETICS Deletion (18q21) GENE DCC (Tumor suppressor gene) of 58
03-01-2008, 08:29 AM
Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Neurofibromatosis type 1 GENETICS Deletion (17q11.2) GENE NF1 (Tumor suppressor gene) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Neurofibromatosis type 2 GENETICS Deletion (22q11) GENE NF2 (Tumor suppressor gene) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Melanoma GENETICS Deletion (9p21) GENE MTS1/MTS2/CDK41 (Tumor suppressor genes) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description B-cell lymphoma GENETICS Translocation (11;14) (q13;q32) GENE Oncogenes: BCL1 (11q13.3), IgH (14q32) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Ewing's sarcoma GENETICS Translocation (22;21) (q12;q22) Translocation (11;22) (q24;q12) GENE Oncogenes: ERG (21q22.3), EWS (22q12), FL11 (11q24) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58
03-01-2008, 08:31 AM
Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Neurofibromatosis type 1 GENETICS Deletion (17q11.2) GENE NF1 (Tumor suppressor gene) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Neurofibromatosis type 2 GENETICS Deletion (22q11) GENE NF2 (Tumor suppressor gene) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Melanoma GENETICS Deletion (9p21) GENE MTS1/MTS2/CDK41 (Tumor suppressor genes) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description B-cell lymphoma GENETICS Translocation (11;14) (q13;q32) GENE Oncogenes: BCL1 (11q13.3), IgH (14q32) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Ewing's sarcoma GENETICS Translocation (22;21) (q12;q22) Translocation (11;22) (q24;q12) GENE Oncogenes: ERG (21q22.3), EWS (22q12), FL11 (11q24) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description 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) of 58 Cancer genetics Genetics FlashCard? FlashMode: Off Term Description Alveolar Rhabdomyosarcoma GENETICS Translocation (2;13) (q35;q14) Translocation (1;13) (p36;q14) GENE PAX3 (2q35), FKHR/ALV (13q14), PAX7 (1p36) of 58 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. of 58 Chromosomal susceptibility disorder Genetics FlashCard? FlashMode: Off Term Description 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 of 58 Hematological disorder Genetics FlashCard? FlashMode: Off Term Description 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 of 58 Hematological disorder Genetics FlashCard? FlashMode: Off Term Description 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 of 58 Hematological disorder Genetics FlashCard? FlashMode: Off Term Description 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. of 58 Hematological disorder Genetics FlashCard? FlashMode: Off Term Description 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" of 58 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 of 58
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. 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. |
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