Affected individuals are usually homozygous for the abnormal gene; each unaffected parent will be a heterozygous carrier. Children affected with AR disorders are usually born to unaffected parents, each of whom carries one copy of the variant. If both members of a couple are carriers (or heterozygotes) for this variant, each of their offspring has a 25% chance of being affected. Risk of these disorders varies between populations and is increased by consanguinity.
Examples of autosomal recessive disorders:
- Sickle cell disease
- Thalassemia
- Congenital adrenal hyperplasia
- Cystic fibrosis
- Friedreich ataxia
- Galactosemia
- Glycogen storage diseases
- Hurler syndrome
- Oculocutaneous albinism
- Phenylketonuria
Autosomal recessive disorders often affect metabolic pathways, whereas autosomal dominant disorders often affect structural proteins