Hyperlipidaemic xanthomatosis. I. Increased risk of death from ischaemic heart disease in first degree relatives of 53 patients with essential hyperlipidaemia and xanthomatosis.

Relatives of young patients with ischaemic heart disease have a substantially increased risk of early death from ischaemic heart disease (Slack and Evans, 1966), and family aggregations of death from ischaemic heart disease were noted especially amongst the few patients with essential hyperlipidaemia. Morris, Kagan, Pattison, Gardner, and Raffle (1966) have called attention to the value of raised plasma cholesterol levels in predicting susceptibility to ischaemic heart disease in middle age, and Albrink, Meigs, and Man (1961) have demonstrated an association of early onset ischaemic heart disease with raised triglyceride levels. The risks of early death from ischaemic heart disease are known to be high in patients with essential hyperlipidaemia associated with xanthomatosis (Muller, 1938; Piper and Orrild, 1956; Guravich, 1959; Epstein, Block, Hand, and Francis, 1959), and as the condition seems to be genetically determined (Wheeler and Sprague, 1953; Leonard, 1956; Khachadurian, 1964) there is good reason to suppose that the relatives of these patients may also show an increased risk of death from ischaemic heart disease. Family concentrations have been reported, but clearly not all families with hyperlipidaemia run the same high risk of death from ischaemic heart disease (Harlan, Graham, and Estes, 1966). Exact information as to the risks of death from ischaemic heart disease amongst relatives of patients with essential hyperlipidaemia is lacking, and accordingly a study has been undertaken to estimate these risks, and to identify the families in which the risk is high. The risks of death from ischaemic heart disease in all first degree relatives of the index patients have been