Subsequent to the ascertainment of these cohorts, an additional case of ID with dysmorphic features was referred to us through cytogenetic services at the University of California, San Francisco, California, USA. CNV analysis with a custom designed 105K microarray identified a maternally inherited 146 kb deletion in this patient which spans PTCHD1 exon 1 and upstream regions (chrX:23,146,927-23,293,273, hg18).
