Paediatrics – MCQ 50 – Gene expression

The process underlying differences in expression of a gene according to which parent has transmitted is called:
A. Anticipation
B. Mosaicism
C. Non penetrance
D. Genomic imprinting

Correct answer : D. Genomic imprinting

In genomic imprinting, a gene / group of genes on the paternal or maternal chromosome is selectively inactivated. The functional allele will be provided by the counterpart.
Example:

• Angelman syndrome – deletion of maternal gene
• Prader Willi syndrome – deletion of paternal gene