LRTOMT and Down syndrome: In the present study, we performed whole-exome sequencing on a Moroccan family with autosomal recessive, non-syndromic hearing loss (ARNSHL), which did not show mutation in the most common genes involved in the Moroccan deaf population, like GJB2 [30], LRTOMT2 [31], TBC1D24 [32] and TMC1 [33].