The fact that Usher syndrome is an autosomal recessive disorder means that
A)both parents must carry the gene,and there is a 50% chance of the child having the syndrome.
B)one parent can carry the gene,and there is a 25% chance of the child having the syndrome.
C)both parents must carry the gene,and there is a 25% chance of the child having the syndrome.
D)one parent can carry the gene,and there is a 50% chance of the child having the syndrome.

Question

Quizplus · Accepted Answer

Autosomal recessive disorders require both parents to carry the gene for there to be a chance of the child inheriting the disorder. If both parents carry the gene, there is a 25% chance of the child having the disorder. Choice A is incorrect because it incorrectly implies that the child will always have the syndrome if both parents carry the gene, when in fact there is only a 50% chance. Choice B is incorrect because it implies that only one parent needs to carry the gene, which is not true for autosomal recessive disorders. Choice D is incorrect because it incorrectly implies that there is a 50% chance if only one parent carries the gene, when in fact the chance is 0% unless the other parent also carries the gene.

The Fact That Usher Syndrome Is an Autosomal Recessive Disorder