Genetic mutations in patients with possible familial hypercholesterolaemia in South East Scotland

Familial hypercholesterolaemia (FH) is one of the most common genetic disorders in the general population. Genetic testing of this condition is increasingly available in the UK to confirm its diagnosis, but the strategies of genetic testing vary. In this pilot study, we sought to investigate whether a strategy that focuses on the low-density lipoprotein receptor (LDLR) and apolipoprotein B (APOB) genes can identify the majority of genetic variants in patients with possible FH in South East Scotland. Forty patients with a clinical diagnosis of possible FH according to the Simon Broome criteria were recruited in a lipid clinic serving South East Scotland. All 18 exons of the LDLR gene were sequenced and multiplex ligation probe amplification was performed to identify major deletions and duplications. Variants of the APOB gene at codon 3527 were investigated by direct sequencing. Genetic mutations were detected in 45% of the patients. Sixteen patients (40%) were found to have mutations in their LDLR gene, whereas two other patients (5%) were identified as heterozygous for the APOB variant commonly associated with FH (c.10580G>A; p.R3527Q). None of these genetic variants were detected in more than two patients. Multiple genetic mutations are associated with a clinical phenotype of FH in South East Scotland. A genetic testing strategy which focuses on a limited number of mutations is unlikely to confirm the diagnosis of FH in the majority of patients in this part of Scotland.