Inbreeding in human populations and its influence on fertility and health

Abstract

In many Asian and African countries, marriages between close biological relatives account for 20 to over 50 percent of all unions, with no evidence of any significant decline to popularity. Inbred unions are characterized 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). Improved public health regimes will lead to a continuing global reduction in the prevalence of infectious diseases, and as a result genetic disorders can be expected to account for an increasing proportion of ill-health. This burden will fail disproportionately on populations in which consanguinity is strongly favoured, including migrant communities from less developed countries now resident in Western Europe, North America and Oceania. However, the nature and degree of the biological problems associated with consanguinity remain to be clearly defined, and it is important that the social and economic benefits of marriage to a dose relative also are taken into consideration. Thus there is an urgent need for extended studies into the entire topic of human inbreeding, which to date has been the focus of little inter-disciplinary research.

Keywords:

• Consanguinity
• Reproductive behaviour
• Morbidity
• Mortality