"In Pakistan, however, some 60 per cent of marriages are between first cousins; the frequency in Bradford and Leeds is thought to be comparable. The result is that clinical genetics units serving the British Pakistani community see a range and frequency of genetic disorders unknown elsewhere in the country. ... "
Cause: Victims of excessive inbreeding.
hasidic jews often marry cousins and have you ever noticed that almost all their kids need eyeglasses at an early age?it could be that nearsightnedness is inherited in those cases as well as Tay-Sachs disease.-this can apply to any group that is isolated either by geography or cultural exclusivity when it comes to marriage-my son and daughter are jewish-honduran-puerto rican and my grandaughter adds black and american indian to the mix-guess what-no eyeglasses!