Which inheritance pattern is associated with Hemophilia B?

Hemophilia B is characterized by a deficiency in factor IX, a critical protein in the blood coagulation cascade. This disorder is inherited in an X-linked recessive manner, meaning that the gene responsible for the condition is located on the X chromosome.

In X-linked recessive inheritance, males, who possess only one X chromosome, are more frequently affected by conditions linked to mutations on that chromosome. In contrast, females have two X chromosomes, so they can be carriers of the gene mutation without expressing the disease if they have one normal copy. However, if a female inherits two copies of the mutated gene (one from each parent), she will express the condition.

This pattern of inheritance is significant in understanding the risk of passing the condition to offspring. Males with hemophilia B will transmit the mutated gene to all of their daughters (who will become carriers) but none of their sons (who inherit their father's Y chromosome). Carrier females have a 50% chance of passing the mutated gene to each child, regardless of gender.

The other inheritance patterns listed—autosomal dominant, autosomal recessive, and Y-linked—do not apply to Hemophilia B. Autosomal dominant conditions typically manifest in every generation, while autosomal recessive