An autosomal recessive trait requires homozygosity or compound heterozygosity to manifest the disease phenotype. Features of autosomal recessive inheritance seen here include:
- Absence of family history of disease in prior generations
- 25% affected status rate among siblings of the affected proband
- Consanguinity
Carriers are denoted by a dot in the center of the circle or square symbol; carrier status in a pedigree can also be depicted by shading half of the symbol. The double line denotes consanguineous reproduction between first cousins. Refer to UpToDate topics on genetic counseling and patterns of Mendelian inheritance for additional information.
