45. Autosomal Recessive Inheritance
In autosomal recessive inheritance, two copies of the allele are required for the trait to be expressed. Carriers of one disease allele will not develop the illness, and several generations may be unaffected, leading to the appearance of skipped generations. Males and females are equally affected. If both parents carry one copy of the recessive allele, one in four offspring, on average, will express the trait.