Pseudodominant Inheritance

Question 1

____, one of the commonest inherited conditions, exhibits so - called _____. It results in a mild intermittent ____, often precipitated by an intercurrent illness.

Answer 1

Gilbert syndrome; pseudodominant inheritance; unconjugated hyperbilirubinaemia

Question 2

The underlying molecular basis in individuals affected with Gilbert syndrome is homozygosity for an insertion
(A(TA)7TAA) within the promoter region of the ____ gene on chromosome ____.

Answer 2

UDP Glucuronosyltransferase Family 1 Member A1 (UGT1A1); 2

Question 3

Mutations within the coding region of UGT1A1 that cause inactivation of the protein rather than merely reducing promoter activity can give rise to the rarer and much more severe autosomal recessive condition known as ____, in w/c there is a severe unconjugated hyperbilirubinaemia.

Answer 3

Crigler – Najjar syndrome type 1

Question 4

Pseudodominant inheritance has also been observed in other conditions such as ____ &, ____. It is more likely to be seen in families in w/c there is ____

Answer 4

Friedreich ataxia; pseudoxanthoma elasticum; consanguinity