Question

A recessive X-linked disorder will exhibit which of the following features (assume the mother has a heterozygous genotype)?

a) Affected sons, carrier daughters
b) Affected daughters, carrier sons
c) Affected sons, unaffected daughters
d) Unaffected sons, unaffected daughters

Answer 1

The correct option is a) Affected sons, carrier daughters. A recessive X-linked disorder will exhibit affected sons, and carrier daughters. Sons have a 50% chance of inheriting the affected allele and being affected by the disorder. Daughters have a 50% chance of being carriers but do not exhibit symptoms themselves.

Step-by-step explanation:

A recessive X-linked disorder will exhibit affected sons, and carrier daughters. When a mother is heterozygous for an X-linked recessive disorder, she carries one normal allele and one affected allele on one of her X chromosomes. Sons have a 50% chance of inheriting the affected allele and therefore being affected by the disorder.

Daughters have a 50% chance of being carriers, meaning they carry the affected allele but do not exhibit symptoms themselves. A recessive X-linked disorder will exhibit affected sons, and carrier daughters. Sons have a 50% chance of inheriting the affected allele and being affected by the disorder. Daughters have a 50% chance of being carriers but do not exhibit symptoms themselves.