Familial hypercholesterolemia (FH) [MIM:143890]: A common autosomal dominant disorder characterized by elevated serum low-density lipoprotein (LDL) cholesterol levels, which result in excess deposition of cholesterol in tissues and leads to xanthelasma, xanthomas, accelerated atherosclerosis and increased risk of premature coronary heart disease. The disorder occurs in 2 clinical forms: a mild form that becomes evident in the fourth or fifth decade in individuals carrying heterozygous LDLR mutations; a more severe form that usually manifests in the first two decades of life in individuals with homozygous LDLR mutations. {ECO:0000269|PubMed:10090484, ECO:0000269|PubMed:10206683, ECO:0000269|PubMed:10422803, ECO:0000269|PubMed:10447263, ECO:0000269|PubMed:10532689, ECO:0000269|PubMed:10660340, ECO:0000269|PubMed:10882754, ECO:0000269|PubMed:10978268, ECO:0000269|PubMed:10980548, ECO:0000269|PubMed:11298688, ECO:0000269|PubMed:11462246, ECO:0000269|PubMed:1446662, ECO:0000269|PubMed:1464748, ECO:0000269|PubMed:17142622, ECO:0000269|PubMed:17347910, ECO:0000269|PubMed:1867200, ECO:0000269|PubMed:19318025, ECO:0000269|PubMed:19319977, ECO:0000269|PubMed:22160468, ECO:0000269|PubMed:22509010, ECO:0000269|PubMed:2318961, ECO:0000269|PubMed:24529145, ECO:0000269|PubMed:25378237, ECO:0000269|PubMed:25545329, ECO:0000269|PubMed:2569482, ECO:0000269|PubMed:2726768, ECO:0000269|PubMed:3263645, ECO:0000269|PubMed:3955657, ECO:0000269|PubMed:7550239, ECO:0000269|PubMed:7573037, ECO:0000269|PubMed:7583548, ECO:0000269|PubMed:7635461, ECO:0000269|PubMed:7635482, ECO:0000269|PubMed:7649546, ECO:0000269|PubMed:7649549, ECO:0000269|PubMed:8168830, ECO:0000269|PubMed:8347689, ECO:0000269|PubMed:8462973, ECO:0000269|PubMed:8664907, ECO:0000269|PubMed:8740918, ECO:0000269|PubMed:9026534, ECO:0000269|PubMed:9104431, ECO:0000269|PubMed:9143924, ECO:0000269|PubMed:9254862, ECO:0000269|PubMed:9259195, ECO:0000269|PubMed:9452094, ECO:0000269|PubMed:9452095, ECO:0000269|PubMed:9452118, ECO:0000269|PubMed:9654205, ECO:0000269|PubMed:9678702, ECO:0000269|PubMed:9852677, ECO:0000269|Ref.71}. Note=The disease is caused by mutations affecting the gene represented in this entry.