27th February 2024

Autosomal recessive

Recessive traits only present themselves in the homozygous genotype. Heterozygote genotypes will typically not display the phenotype of the condition and will serve as carriers for the condition. In a typical pedigree, the parents of the affected patient will not show the phenotype of the condition. In addition, there will be equal incidence between male and female patients. The condition will typically present within a single-family unit without affecting other family units within the family tree. Heterozygote parents will have a 1 in 4 chance of having a child affected by the condition. A recessive condition can be amplified within a consanguineous relationship due to the higher chances of the recessive alleles pairing up.

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