27th February 2024

Autosomal dominant

Autosomal dominant traits can present themselves in individuals with the heterozygous genotype. A vertical pedigree will be observed, with most generations having at least one affected individual. Each affected individual will have one parent affected by the same condition. Male-to-male transmission is possible with equal incidence between males and females within the family tree. Each child will have a 1 in 2 chance of inheriting the mutation if one partner is unaffected by the condition.

Image Source: Wikimedia Commons (2006). Autosomal Dominant Pedigree Chart, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Autosomal_Dominant_Pedigree_Chart.svg (Accessed: 5 January 2024).

A homozygous autosomal dominant genotype is possible, and this typically presents with a more severe phenotype than the heterozygous genotype.