Our genetic scan of WDR45 gene on 32 girls with intellectual disabilities (ID) found two having disease-causing WDR45 variants. Together with our previous findings from 19 girls subjected to whole genome sequencing, WDR45 variants accounts for 12% of female ID patients, apparently suggesting its major role in female ID patients. We also performed an extensive X chromosome inactivation study on one individual with a novel variant showing extremely severe phenotype to delineate potential genetic consequence for the phenotypic spectrum of the WDR45 variants. (By Dr. Chihiro Abe-Hatano, https://jmg.bmj.com/content/early/2024/10/28/jmg-2024-110068 )