Both members of an expectant couple are carriers for phenylketonuria (PKU),an autosomal recessive disorder.In counseling them about the risk to their unborn child,the nurse should tell them that
A) the child has a 25% chance of being affected.
B) the child will be a carrier, like the parents.
C) the child has a 50% chance of being affected.
D) one of four of their children will be affected.

Question

Quizplus · Accepted Answer

Each child born to a couple who carries an autosomal recessive trait has a 25% chance of having the disorder,because the child receives either a normal or an abnormal gene from each parent.If one member of the couple has the autosomal recessive disorder,all of their children will be carriers.If both parents are carriers,each child has a 50% chance of being a carrier.Each child has the identical odds of being affected.

Both Members of an Expectant Couple Are Carriers for Phenylketonuria