Autosomal dominant is a pattern of Mendelian inheritance whereby an affected individual possesses one copy of a mutant allele and one normal allele. (In contrast, recessive diseases require that the individual have two copies of the mutant allele.) Individuals with autosomal dominant diseases have a 50-50 chance of passing the mutant allele and hence the disorder onto their children. Examples of autosomal dominant diseases include Huntington's disease, neurofibromatosis, achondroplasia (in some cases), and polycystic kidney disease.

Compare with autosomal recessive.