While MS MS results indicated hyperalanineemia for NB-10 and maple syrup disease for NB-11 and NB-12, gene testing identified compound heterozygous variants of uncertain significance in other IEM genes SARDH, MMACHC and ETFDH related to sacrosinuria, methylmalonic aciduria and glutaric aciduria, respectively. The gene discussed is MMACHC; the disease is glutaric aciduria.