MSL3 and neurodevelopmental disorder: MSL3 was first identified as a candidate gene in the Deciphering Developmental Disorder Study13 and was recently described as the underlying genetic cause of Basilicata–Akhtar syndrome (MIM 301032), a novel X-linked neurodevelopmental disorder that equally affects female and male individuals.14 In a total of 16 patients (including two siblings), exome sequencing revealed a variety of associated variant types in MSL3, but mainly loss-of-function variants.