Similarly, a heterozygous single-nucleotide variant (SNV) in the DSCAM gene also caused ERK1/2 pathway dysregulation, with significantly low levels of p27hospho-ERK1/2 in neurons derived from DSCAM-mutated hIPSCs [302], while heterozygous mutation in exon 15 of TSC1 led to mTOR and ERK1/2 activation, along with the differential expression of genes known to be linked with ASD, epilepsy and ID [305]. The gene discussed is MAPK3; the disease is epilepsy.