Molecular genetics of familial hypercholesterolaemia in Norway

Objectives. To characterize mutations in the low density lipoprotein (LDL) receptor gene causing familial hypercholesterolaemia (FH) amongst Norwegian patients. Design. Molecular genetic analyses of the LDL receptor gene have been performed in patients with a clinical diagnosis of FH. Subjects. A total of 742 probands have been studied. Of these, 476 had a diagnosis of definite FH. The rest had a diagnosis of possible FH. Results. Twenty-three different mutations in the LDL receptor gene as well as the apolipoprotein B-3500 mutation have been found. Six of the mutations in the LDL receptor gene are novel mutations. A molecular genetic diagnosis was achieved in 295 of the probands with definite FH (62%) and in 317 probands total. Of the 317 probands, 3% carried the apolipoprotein B-3500 mutation. When family members were included, a total of 624 persons carried a mutation in the LDL receptor gene and 20 carried the apolipoprotein B-3500 mutation. Conclusions. Approximately 5% of Norwegian FH patients have been provided with a molecular genetic diagnosis. Our data suggest that molecular diagnosis of FH in Norway is feasible and should be implemented in clinical medicine.