Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
A newborn presents with severe acidosis, vomiting, hypotonia, and neurologic deficits. Serum analysis reveals elevated levels of lactate and alanine. These observations suggest a deficiency in which of the following enzymes?
A. Alanine aminotransferase
B. Glutamate dehydrogenase
C. Lactate dehydrogenase
D. Pyruvate carboxylase
E. Pyruvate dehydrogenase
Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
The correct answer is E. Pyruvate dehydrogenase (PDH) catalyzes the irreversible conversion of
pyruvate to acetyl-CoA. If PDH is absent, pyruvate will be used in other pathways instead. Pyruvate will be converted to alanine via alanine aminotransferase (choice A) and to lactate via lactate dehydrogenase (choice C). Glutamate dehydrogenase (choice B) is involved in oxidative deamination, releasing ammonium ion for urea synthesis. Deficiency of this enzyme would not cause the symptoms described. Pyruvate carboxylase (choice D) is a gluconeogenic enzyme that catalyzes the conversion of pyruvate to oxaloacetate. Deficiency of this enzyme would not cause the symptoms described.
Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
If Pyruvate carboxilase is deficit alanine and lactate will increase too.. .
Can somebody please explain to me the sign and symptoms of Pyruvate Carboxilasa deficit???? THX
