Prevalence of four Mendelian disorders associated with autism in 2392 affected families

Autism spectrum disorder (asd) is a neurobehavioral disorder with a heterogeneous genetic etiology. based on the literature, several single-gene disorders, including rett syndrome, smith-lemli-opitz syndrome, pten hamartoma tumor syndrome and tuberous sclerosis, are associated with a high prevalence of asd. we estimated the prevalence of these four conditions in a large cohort of patients using whole-exome sequencing data from 2392 families (1800 quads and 592 trios) with asd from the national database for autism research. seven patients carried a pathogenic or likely pathogenic variant in either tsc1, tsc2, pten, dhcr7 or mecp2, with 6 out of 7 reportable variants occurring in pten (1 in 399).