ISL1 and epilepsy: Interestingly, several known autism and epilepsy candidate genes, namely distal-less homebox 2 (DLX2), aristaless related homeobox (ARX), ISL LIM homeobox 1 (ISL1), neuroligin 1 (NLGN1), SH3 and multiple ankyrin repeat domains 1 (SHANK1), adenosine A2A receptor (ADORA2A), and distal-less homeobox 5 (DLX5), were found in the list of genes differentially expressed and downregulated in AS or idic(15).