INBREEDING IN HUMAN-POPULATIONS AND ITS INFLUENCE ON FERTILITY AND HEALTH

In many Asian and African countries, marriages between close biologica l relatives account for 20 to over 50 per cent of all unions, with no evidence of any significant decline in popularity. Inbred unions are c haracterized by greater fertility, although they also result in higher levels of post-natal morbidity and mortality due to the expression of detrimental recessive genes inherited from a common ancestor(s). Impr oved public health regimes will lead to a continuing global reduction in the prevalence of infectious diseases, and as a result genetic diso rders can be expected to account for an increasing proportion of ill-h ealth. This burden will fall disproportionately on populations in whic h consanguinity is strongly favoured, including migrant communities fr om less developed countries now resident in Western Europe, North Amer ica and Oceania. However, the nature and degree of the biological prob lems associated with consanguinity remain to be clearly defined, and i t is important that the social and economic benefits of marriage to a close relative also are taken into consideration. Thus there is an urg ent need for extended studies into the entire topic of human inbreedin g, which to date has been the focus of little inter-disciplinary resea rch.