Who can pass on hemophilia to daughters?

Hemophilia is a genetic disorder that primarily affects males, as it is linked to the X chromosome. The gene responsible for hemophilia is recessive, meaning that a daughter must inherit the affected gene from both parents to express the disorder.

An affected father has one X chromosome that carries the hemophilia gene; therefore, he can pass this X chromosome to his daughters. Consequently, all daughters of an affected father will inherit his X chromosome that contains the hemophilia gene. These daughters will be carriers of the disorder if their mothers are not affected by hemophilia themselves.

In contrast, an affected mother can pass the affected X chromosome to her sons, resulting in the expression of hemophilia in them, but she can also pass a normal X chromosome to her daughters, allowing them not to be affected. This means that while affected mothers can pass on the hemophilia gene, they cannot guarantee that their daughters will inherit it.

In the case of both parents, it is important to note that the father, being affected, will always pass an affected X to his daughters, while the mother’s contribution varies.

Thus, the most straightforward route for a daughter to receive the gene for hemophilia is certainly through an affected father