We examined, from a cohort of 165 families, 529 individuals for familial hypercholesterolemia (FH). Utilising clinical criteria for diagnosis, we identified 122 patients (n=41 families) as having FH. With PCR testing, 31 individuals (n=12 families) were found to have familial defective Apo B-100 (FDB). From the cohort, 102 normolipidemic (NL) individuals served as a control group. Patients with FH had the highest levels of total cholesterol (TC), LDL-cholesterol (LDL-C) and apolipoprotein B (Apo B), followed by FDB patients and the normolipidemic relatives had the lowest levels (P<0.0001 for all parameters). We did not find any effect of Apo E genotypes on lipid levels in the NL or FH group. Therefore, other genetic and/or environmental factors may be responsible for the diversity in the clinical expression in these populations.