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. The gene discussed is CBLC; the disease is vitamin B12 deficiency.