n. the presence of elevated concentrations of cholesterol in the blood (see also hyperlipidaemia), which predisposes to atheromatous disease (see atheroma). Familial hypercholesterolaemia is an autosomal dominant condition in which raised levels of low-density lipoprotein (LDL) result from a mutation in the LDL receptor gene, producing a deficiency of LDL receptors, which normally remove cholesterol from the circulation. The heterozygous state, with LDL levels of 5–10 mmol/1, may not be detected until adulthood; usual signs are tendon xanthomas on the backs of the hands and a corneal arcus. The homozygous state is much more serious as cardiovascular complications can occur in childhood, due to massively increased total cholesterol levels (>12 mmol/1).
Subjects: Medicine and Health.