autosomal-dominant inheritance

autosomal-dominant inheritance,

a pattern of inheritance in which the transmission of a dominant allele on an autosome causes a trait to be expressed. Males and females are usually affected with equal frequency. If both parents are heterozygous (Aa), each of their children has a 50% chance of being heterozygous, a 25% chance of being homozygous for the dominant allele (AA), and a 25% chance of being homozygous for the recessive allele (aa); children with either of the first two genotypes will express the trait of the dominant allele. If one parent is homozygous for the dominant allele, all of the children will express the trait. Achondroplasia, osteogenesis imperfecta, polydactyly, Marfan's syndrome, and some neuromuscular disorders are transmitted through autosomal-dominant inheritance. Compare autosomal-recessive inheritance. See also dominance.