A genetic counselor will know that the probability of having a child affected with a condition inherited as an autosomal recessive would be:

A) 0.5 or 50% if both parents were homozygous normal
B) 0.5 or 50% if both parents were heterozygous
C) 0.25 or 25% if both parents were homozygous normal
D) 0.25 or 25% if both parents were heterozygous
E) 0% if both parents were heterozygous

Autosomal Recessive

A mode of inheritance in which a trait or disorder is expressed only when two copies of a mutant gene are present, one from each parent.

Homozygous Normal

A genetic condition where an individual has two identical alleles for a trait that are considered the standard or "normal."

Heterozygous

Having two different alleles at the same locus on a chromosome, resulting in genetic variation for a particular trait.