SLC25A2 and Decreased circulating vitamin B12 concentration: In addition, 30 mutations in nine IEMs-associated genes were identified in the 28 confirmed cases and 19 cases with the mutations in phenylalanine hydroxylase (PAH), solute carrier family 22 member 5 (SLC22A5), and methylmalonic aciduria (cobalamin deficiency) cblC type with homocystinuria (MMACHC) genes, respectively, leading to the high incidence of phenylketonuria, primary carnitine deficiency, and methylmalonic acidemia, respectively.