DDX3X and Premature aging appearance-developmental delay-cardiac arrhythmia syndrome: Hemizygous variants were identified in two known X-linked disease genes: NAA10 (Ogden syndrome, ID and long QT, MIM 300855); and DDX3X previously associated with X-linked ID (MIM 300958) (Table 1, Additional file 3: Table S2) [41, 57–65].