Characterization of Greater Middle Eastern genetic variation for enhanced disease gene discovery

Joseph Gleeson and colleagues report whole-exome sequencing of a cohort of over 1,000 individuals from the Greater Middle East, characterizing common and rare variants. They find evidence of subregional diversity and historical migrations and use the GME Variome to identify disease-causing mutations. The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Persian Gulf region, North Africa, and Central Asia 1 , 2 , 3 , has resulted in an elevated burden of recessive disease 4 . Here we generated a whole-exome GME variome from 1,111 unrelated subjects. We detected substantial diversity and admixture in continental and subregional populations, corresponding to several ancient founder populations with little evidence of bottlenecks. Measured consanguinity rates were an order of magnitude above those in other sampled populations, and the GME population exhibited an increased burden of runs of homozygosity (ROHs) but showed no evidence for reduced burden of deleterious variation due to classically theorized 'genetic purging'. Applying this database to unsolved recessive conditions in the GME population reduced the number of potential disease-causing variants by four- to sevenfold. These results show variegated genetic architecture in GME populations and support future human genetic discoveries in Mendelian and population genetics.