A DOUBLE MUTANT LDL RECEPTOR ALLELE IN A CYPRIOT FAMILY WITH HETEROZYGOUS FAMILIAL HYPERCHOLESTEROLEMIA

Two novel mutations Q363X and D365E were identified in the low-density lipoprotein receptor gene in a Cypriot patient with heterozygous fami lial hypercholesterolemia. Restriction enzyme analysis of the index ca se and seven of her family members, by using AvaII and PVuII respectiv ely, demonstrated that the two exon 8 mutations are transmitted in cis within the family. The disease phenotype is probably caused by the st op-363 mutation; this would result in a truncated protein that would p robably be rapidly degraded in the extracellular space.