Genetic analysis of four generations of a family reveals that about 50% of the males in the family are affected by a mutation and about 50% of the females are unaffected carriers of the mutation that affects the males. What type of inheritance pattern is seen in this family?

Question

Quizplus · Accepted Answer

Since only males are affected by the mutation and females are carriers, the inheritance pattern is likely X-linked recessive. This means that the mutation is located on the X chromosome, and males have only one X chromosome, while females have two. Therefore, a male only needs to inherit one copy of the mutated gene from his carrier mother to be affected, while a female needs to inherit two copies of the mutated gene (one from each carrier parent) to be affected. This results in a 50% chance of affected males and 50% chance of carrier females. Neither autosomal-dominant nor autosomal-recessive patterns would result in such a gender-specific prevalence. Y-linked inheritance would only be observed in males and is extremely rare.

Genetic Analysis of Four Generations of a Family Reveals That