Consanguinity, cultural variation, ethical and psychosocial factors

Consanguinity is defined as marriage between blood relatives and is commonly used to describe relationships that include up to second cousin marriages (Bittles, 1994). At a biological level, consanguineous unions may increase the risk in the homozygous state in their children [note 1] (Modell and Darr, 2003). This might be reflected in relatively higher probability of an autosomal recessive inherited disease and certain types of congenital malformations. However consanguinity does not increase the risk of autosomal dominant or X-linked disorders. Studies on consanguinity have focussed on the probable higher risk of prenatal or postnatal mortality and/or morbidity due to congenital malformations and/or intellectual disability (Bundey and Aslam, 1993) [note 2].