FAMILIAL DEFECTIVE APOLIPOPROTEIN B-100 - A STUDY OF PATIENTS FROM LIPID CLINICS IN SCOTLAND AND WALES

Familial defective apolipoprotein (apo) B-100 (FDB) is an autosomal co dominant disorder, which may be associated with hypercholesterolaemia. The defect is caused by the substitution of glutamine for arginine at amino acid residue 3500 of apo B-100. A total of 357 hypercholesterol aemic patients, 48 with a clinical diagnosis of familial hypercholeste rolaemia attending lipid clinics in Scotland and Wales, were screened for the presence of FDB. Seven unrelated individuals, five of whom had a family history of coronary heart disease, and a further 11 first-de gree relatives, were shown to be heterozygous for the mutation. Pedigr ee analysis demonstrated the mutation to be present on a single haplot ype, suggesting that in Britain it is inherited from a common ancestor . Treatment of 11 heterozygous individuals with lipid-lowering medicat ion showed falls in total and low density lipoprotein cholesterol rang ing from 11.6 to 38.8% and 5.3 to 49.5%, respectively. In view of the condition's association with coronary heart disease and hypercholester olaemia, it may be worthwhile identifying carriers attending lipid cli nics, so that affected siblings can be offered cholesterol-lowering tr eatment where necessary.