Cousin marriage isn’t a specifically Pakistani thing. At the levels it occurs at in the Pakistani community it is basically a Muslim thing though. The only non-Muslim country that falls in the Muslim range is India which has about the same population prevalence as Turkey. Given the much higher prevalence in Pakistan I’d guess that’s almost entirely due to India’s large Muslim population.

See the image on page 3 of this pdf.

https://www.researchgate.net/profile/Ghazi_Tadmouri/publicat...

Consanguinity and reproductive health among Arabs