Under the supervision my colleague Sara Goodacre, Katalina Bobowik (MRes 2013) sequenced some Bedu cheek-swab samples from individuals of the Jebaliya and Mzeina tribes. In the Mzeina she sampled some deaf individuals: there is an exceptionally large proportion of the Mzeina who are deaf from birth (6-8%).
She found that these tribes are the lowest and third lowest of all studied populations in their genetic variability. Almost certainly this is the product of their isolation and the tradition of cousin marriages. She also looked for known deafness genes, ruling out all the common ones. It is possible that elements of the Bedouin environment contribute to the expression of the deafness genes. We are currently studying this via a Wellcome Trust Seed grant (2016-2018).