PJA1 and Neurodevelopmental delay: Our exome sequencing did not identify any variants in FAM155B in the patients tested and did not cover LINC00269. Two additional heterozygous missense variants (c.623C>T and c.1457C>A; p.Ser208Phe and p.Pro486His, respectively) in PJA1 were identified in independent female patients of NDD (SIZ‐978 and OKI‐011‐1), but both variants were inherited from hemizygous carrier fathers without NDD symptoms (Table S8 and Supplementary Data).