Answer to Question #72853 in Genetics for Bushra Nasim

Question

Why haemophilia raises in women as compared to men? Reason.

Answer 1

Hemophilia is an X-linked recessive condition. Men have only one X chromosome, and thus, presence of the disease gene always leads to development of hemophilia. In turn, women have two X chromosomes and can be the carrier of the abnormal gene, which does not lead to any manifestations. The woman can pass the disease gene to her son, which makes females the "origin" for hemophilia. In turn, men never pass their X chromosome to the son, while daughters usually have the additional X chromosome with the normal gene and do not develop the disease.