Which of the following enzyme's activity is impaired in Gilbert's syndrome?

Options:
explanation: This is the correct answer. Gilbert's syndrome is an autosomal recessive disorder of bilirubin metabolism in the liver due to a defect in the UDP-glucuronosyltransferase 1 gene. It is a pre-hepatic cause of jaundice which presents with unconjugated hyperbilirubinemia and recurrent episodes of jaundice especially after a trigger such as febrile illnesses, fasting, menstruation, physical exertion and so forth. UDP-glucuronosyltransferase 1 is important for converting unconjugated to conjugated bilirubin (water-soluble), and a defect in the gene results in unconjugated hyperbilirubinemia and pre-hepatic jaundice.
name: UDP-glucuronosyltransferase
label: a
answer: yes
explanation: This is not the correct answer. Gilbert's syndrome is an autosomal recessive disorder of bilirubin metabolism in the liver due to a defect in the UDP-glucuronosyltransferase 1 gene. It is a pre-hepatic cause of jaundice which presents with unconjugated hyperbilirubinemia and recurrent episodes of jaundice, especially after certain triggers. On the other hand, a defect in the ATP7B gene is seen in Wilson disease, which is an autosomal recessive disorder with a characteristic copper-transporting P-type ATPase defect (ATP7B molecular defect) in 80% of cases.
name: ATP7B
label: c
answer: no
explanation: This is not the correct answer. Gilbert's syndrome is an autosomal recessive disorder of bilirubin metabolism in the liver due to a defect in the UDP-glucuronosyltransferase 1 gene. It is a pre-hepatic cause of jaundice which presents with unconjugated hyperbilirubinemia and recurrent episodes of jaundice, especially after certain triggers. On the other hand, G6PD is the catalyst in the rate-limiting first step of the pentose phosphate pathway, and a deficiency can result in acute haemolytic anaemia.
name: glucose-6-phosphate dehydrogenase (G6PD)
label: d
answer: no
explanation: This is not the correct answer. Gilbert's syndrome is an autosomal recessive disorder of bilirubin metabolism in the liver due to a defect in the UDP-glucuronosyltransferase 1 gene. It is a pre-hepatic cause of jaundice which presents with unconjugated hyperbilirubinemia and recurrent episodes of jaundice, especially after certain triggers. On the other hand, Congenital Adrenal Hyperplasia (CAH) is a group of inherited, autosomal recessive genetic disorders caused by enzyme defects in the adrenal cortex, which disrupts steroid hormone synthesis. The most common variant is a 21-hydroxylase deficiency.
name: 21-hydroxylase
label: b
answer: no
explanation: This is not the correct answer. Gilbert's syndrome is an autosomal recessive disorder of bilirubin metabolism in the liver due to a defect in the UDP-glucuronosyltransferase 1 gene. It is a pre-hepatic cause of jaundice which presents with unconjugated hyperbilirubinemia and recurrent episodes of jaundice, especially after certain triggers. On the other hand, Pyruvate kinase deficiency is an autosomal recessive non-spherocytic anaemia which can present with unconjugated hyperbilirubinaemia (pre-hepatic jaundice) and hepatosplenomegaly.
name: Pyruvate kinase
label: e
answer: no

Correct answer: a