Parents of a child with cystic fibrosis ask the nurse about genetic implications of the disorder. Which statement, made by the nurse, expresses accurately the genetic implications?
A) If it is present in a child, both parents are carriers of this defective gene.
B) It is inherited as an autosomal dominant trait.
C) It is a genetic defect found primarily in non-Caucasian population groups.
D) There is a 50% chance that siblings of an affected child also will be affected.

Question

Quizplus · Accepted Answer

CF is an autosomal recessive gene inherited from both parents and is inherited as an autosomal recessive, not autosomal dominant, trait. CF is found primarily in Caucasian populations. An autosomal recessive inheritance pattern means that there is a 25% chance a sibling will be infected but a 50% chance a sibling will be a carrier.

Parents of a Child with Cystic Fibrosis Ask the Nurse