Question

A nurse is teaching a class on X-linked recessive disorders. Which of the following statements would the nurse most likely include?A) Males are typically carriers of the disorders.B) No male-to-male transmission occurs.C) Daughters are more commonly affected withthe disorder.D) Both sons and daughters have a 50% risk ofthe disorder.

Answer 1

Answer:

B) No male-to-male transmission occurs

Explanation:

X-linked recessive disorder are passed via X chromosomes. A female with two recessive alleles will have the disorder while a female with one recessive allele will be a carrier. Since a male has only one X chromosome, having a single copy of the recessive allele is enough to make him affected. Hence, males can not be carrier of these disorders, they will either be affected or unaffected.

Sons are also more commonly affected by this disorder since they require only one recessive allele to express it. Since males pass on Y chromosome to sons and not X chromosome, male to male transmission of the disorder is not possible.