Recent research has focused on the rapid detection of new LDL receptor gene variants and large scale screening for known mutations. Whether the nature of the mutation in the LDL receptor gene in familial hypercholesterolaemia determines clinical variability has been examined, as well as the potential value of detecting mutation carriers for clinical practice. There is also evidence that some patients with clinical familial hypercholesterolaemia do not have detectable defects in the LDL receptor or apolipoprotein B. Curr Opin Lipidol 9:141–147. © 1998 Rapid Science Ltd