Background: Patients with familial hypercholesterolaemia have increased risk of developing coronary heart disease. The most cost-effective way of diagnosing patients with familial hypercholesterolaemia is to perform genetic testing of close relatives of already diagnosed patients.
Material and methods: Probands with familial hypercholesterolaemia in whom the underlying mutation in the low-density lipoprotein receptor gene has been identified were informed that close relatives should also be tested.
Results: Blood samples were taken for molecular genetic testing from 851 first-degree relatives of patients with familial hypercholesterolaemia; 47.8 % tested positively and 52.2 % negatively. Among those with positive tests, only 41.5 % were on lipid-lowering drugs and only 6.1 % had a value for total serum cholesterol < 5 mmol/l. Six months after testing, 81.9 % were on lipid-lowering drugs, at which time a mean reduction in total serum cholesterol of 21.2 % (p < 0.0001) was observed in patients aged 18 and above who were not on treatment at the time of testing.
Interpretation: Molecular genetic testing for familial hypercholesterolaemia in a family-based strategy is a cost-effective way of diagnosing patients with this condition that leads to implementation of effective preventive measures.