Glycine Encephalopathy with Normal Serum Glycine, also known as encephalopathy, glycine, with normal serum glycine, is related to atypical glycine encephalopathy and glycine encephalopathy 1. An important gene associated with Glycine Encephalopathy with Normal Serum Glycine is SLC6A9 (Solute Carrier Family 6 Member 9). Affiliated tissues include brain, and related phenotypes are microcephaly and optic atrophy