These five pathogenetic HDV loci are associated with the susceptibility of osteopetrosis (CLCN7), hearing loss (GJB2), cardiomyopathy (PRDM16), arrhythmogenic right ventricular dysplasia 1 (TGFB3), and sucrase-isomaltase deficiency (SI), respectively. The gene discussed is SI; the disease is osteopetrosis.