A Novel Mutation in Exon 4 of the Low Density Lipoprotein (LDL) Receptor Gene in an Iranian Familial Hypercholesterolemia Patient

Familial hypercholesterolemia (FH) is an autosomal co-dominant disorder of lipid metabolism, caused by mutations in LDL receptor gene. The penetrance of FH is almost 100%, meaning that half of the offspring of affected parents born with disease. The patients are at risk of premature coronary heart disease (CHD). There is no report about the molecular basis of FH in Iran. Identification of mutations allows unequivocal diagnosis in potentially affected relatives. To characterize genetic aberrations in Iranian FH patients, after ruling out the most common mutation producing familial defective ApoB-100 (R3500Q), we screened exon 4 in LDL receptor gene in 30 heterozygous FH patients by single strand conformation polymorphism (SSCP). A new missense mutation (445G>T) was found in proband and his mother. This causes a Gly to Cys change in repeat 3 of LDL binding domain. This nucleotide change was not found in 50 normal individuals