It is a gene problem. It comes from marrying your first cousin and having children. That will screw up the genes of the children. Congenital problems in the Arab World are off the charts high.
As a teenager I boarded in school with a guy from Lybia whose grandmothers were identical twins! On top of all the generational inbreeding that’s gotta really accentuate one’s recessive genes to become dominant. He was actually a pretty decent guy but darn...