Autosomal dominant inheritance

Autosomal-Dominant-inheritance-small-image

Used to describe a characteristic or condition that appears in an individual who is a heterozygote (i.e. a person who has one usual and one altered gene of a particular pair).

Autosomal dominant conditions

With an autosomal dominant condition, an alteration in one copy of the gene is sufficient to impair cell function, leading to disease.  The alteration is located on an autosome.

AD-pedigree-example

Features of autosomal dominant inheritance that you may see on a family tree include:

  • people with the condition in each generation
  • males and females affected in roughly equal proportions
  • all forms of transmission present (male to female, male to male, female to male and female to female).

At conception, each child has a 1 in 2 (50%) chance of inheriting the condition.