MVK and Decreased circulating vitamin B12 concentration: In 2008, a genome-wide association study (GWAS) conducted in populations of European descent discovered novel loci at chromosome 12q24, which includes mevalonate kinase (MVK), methylmalonic aciduria (cobalamin deficiency) cbIB type (MMAB), and potassium channel tetramerization domain-containing 10 (KCTD10), all of which influence HDL-C concentrations [13].