NLGN4X and autism: Of the 17 ASD patients, 10 had non-syndromal autistic disorder with known genetic alterations: two of these patients were monozygotic male twins with a chromosome 3p26.2 deletion, not involving any reported gene, one had a chromosome 2p21 duplication and a chromosome 20p21.1 deletion, three had SHANK3 mutations, two had NLGN4 mutations, and one had a balanced translocation involving chromosomes 14 and 15.