Abstract 50

Diagnosis of heterozygous familial hypercholesterolemia, an autosomal dominant genetic disorder with an estimated prevalence of 1/500 is difficult, because plasma lipid levels overlap with those of the general population. Using DNA tests to confirm the diagnosis of FH have suggested that between 15-20% of adult subjects may by misdiagnosed by cholesterol testing alone(Ward, 1996).

A proportion of children who are at risk for FH (carriers of a mutation causing FH) may present initially with lipid levels within a normal range and elevated levels may develop at a later age (Kessling et al, 1990).

Within the MED-PED project we were able to detect out of 13 children with clinical diagnosis of FH 11 heterozygous, 1 homozygous and 1 ApoB 100 variant. At least one child would have been missed using the common criteria for first degree relatives of patients with FH (> 220 mg/dl Chol). Using the criteria for the general population (> 270 mg/dl Chol) 5 adolescents would have been missed.

Thus, diagnosis of FH by means of DNA - analysis of LDL-receptor mutations seems to be an appropriate diagnostic tool for early detection of children and adolescents who are at later risk for cardiovascular diseases.

This procedure enables prevention strategies even in adolescence.