Recent GWASes have found several novel loci at chromosome 12q24, including the mevalonate kinase (MVK) and methylmalonic aciduria (cobalamin deficiency) cblB type (MMAB) genes, both of which influence high-density lipoprotein cholesterol (HDL-C) levels [14, 15]. The gene discussed is MMAB; the disease is Decreased circulating vitamin B12 concentration.