Unlike other hereditary hemochromatosis—which mostly occurs in individuals of >30 years of age, rarer subtypes of HJV-related type 2A and HAMP (encoding hepcidin)-related type 2B hemochromatosis, which usually develop in the first to third decades of life—causes severe clinical complications, such as liver fibrosis, hepatocellular carcinoma, diabetes, hypogonadism, and heart failure; HJV-related type 2A hemochromatosis is referred to as juvenile hemochromatosis (JH) [1,5]. The gene discussed is HAMP; the disease is diabetes mellitus.