Answer to Question #154541 in Genetics for Ashwani Kumar Gupta

Question

The recessive genes for hemophilia A and agamoglobulinemia are 6.4 map units apart

on the X chromosome. What is the probability of having a child with both anomalies in a family

where the father has hemophilia and the mother carries both recessive genes passed on from her

mother?

Answer 1

Haemophilia is a mostly inherited genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding. As haemophilia A and B are both X-linked recessive since a male receives his single X-chromosome from his mother, the son of a healthy female silently carrying the deficient gene will have a 50% chance of inheriting that gene from her and with it the disease; and if his mother is affected with haemophilia, he will have a 100% chance of being a haemophiliac.