The effect of reproductive compensation on recessive disorders within consanguineous human populations.

We investigate the effects of consanguinity and population substructure on genetic health using the UK Asian population as an example. We review and expand upon previous treatments dealing with the deleterious effects of consanguinity on recessive disorders and consider how other factors, such as population substructure, may be of equal importance. For illustration, we quantify the relative risks of recessive lethal disorders by presenting some simple calculations that demonstrate the effect 'reproductive compensation' has on the maintenance of recessive alleles. The results show how reproductive compensation can effectively counteract the purging of deleterious alleles within consanguineous populations. Whereas inbreeding does not elevate the equilibrium frequency of affected individuals, reproductive compensation does. We suggest this effect must be built into interpretations of the incidence of genetic disease within populations such as the UK Asians. Information of this nature will benefit health care workers who inform such communities.