Intellectual Developmental Disorder, X-Linked 1, also known as xlid1, is related to non-syndromic x-linked intellectual disability 1 and intellectual developmental disorder, x-linked 20. An important gene associated with Intellectual Developmental Disorder, X-Linked 1 is IQSEC2 (IQ Motif And Sec7 Domain ArfGEF 2). Affiliated tissues include brain, and related phenotypes are secondary microcephaly and intellectual disability