PTCHD1 and autism: Although estimating the proportion of ASD and ID attributable to PTCHD1 variants is difficult, using the Autism Speaks/MSSNG dataset (accessed December 2024) and using only good-quality hemizygous calls in males with ASD, we estimated that a frequency of 0.32% have a PTCHD1 variant (N = 4762, including affected siblings; loss copy number variants [CNVs] spanning 1 or more PTCHD1 exons [but not multigenic]: n = 3; rare hemizygous missense: n = 12 [6 of which have supportive functional evidence in this study and others]).