Consanguinity

Consanguinity refers to a genetic relationship between individuals who share a common ancestor. The term derives from Latin con- “with” and sanguis “blood.” In genetics and anthropology, it is used to describe marriages or sexual unions between people who are related as second cousins or closer, though the concept applies to any degree of relatedness. The degree of relatedness is often measured by kinship coefficients or the inbreeding coefficient (F).

Genetic implications arise because offspring of related individuals have a higher probability of inheriting identical alleles from a common ancestor. This increases the risk of autosomal recessive disorders and other health problems, with greater risk the closer the relationship. The baseline risk for many congenital or genetic conditions in the general population is about 2–3%, and consanguinity elevates that risk to varying degrees depending on the relationship and population allele frequencies. Not all children from consanguineous unions are affected. Genetic counseling and carrier screening can help assess and manage risk.

Cultural and legal contexts vary widely. Consanguineous marriages are traditional in many regions and cultures and remain common in parts of the Middle East, North Africa, South Asia, and other areas. Legal restrictions range from prohibitions or limitations on certain relative pairs to permissive frameworks that respect cultural practices. Public health programs may address consanguinity through education, community engagement, and screening in populations with higher prevalence.

Healthcare and research on consanguinity examine its associations with reproductive outcomes such as miscarriage, stillbirth, and neonatal mortality, as well as the incidence of rare genetic diseases. While risks exist, many offspring of related parents are healthy, underscoring the nuanced interplay of genetics, culture, and individual choice.