Prevalence and Epidemiology

Abstract

The frequency of consanguineous marriages varies from one population to another. Consanguineous marriage is not restricted to specific religions or to population isolates, but is a long-standing practice in many regions of the world and it continues to be preferred by many populations, with more than 1,000 million people living in countries where between 20% and 50+% of marriages are consanguineous. Levels above 5% occur in the northern part of Africa, the Middle East and parts of Asia, whereas in what is described as the "Western world" – i.e. the entire North American continent, the whole of Europe (with the exception of Spain), Australia and New Zealand – the frequency is less than 1%. In South America, parts of eastern and southeast Asia, Spain and various parts of Africa the rate is between 1 and 10%. In other parts of the world the frequencies are unknown.