A Variant in LDLR is Associated with Abdominal Aortic Aneurysm

Background—Abdominal aortic aneurysm (AAA) is a common cardiovascular disease among older people and demonstrates significant heritability. In contrast to similar complex diseases, relatively few genetic associations with AAA have been confirmed. We reanalysed our genome-wide study and carried through to replication suggestive discovery associations at a lower level of significance.

Methods and Results—A genome-wide association study was conducted using 1,830 cases from the UK, New Zealand and Australia with infra-renal aorta diameter =30mm or ruptured AAA and 5,435 unscreened controls from the 1958 Birth Cohort and National Blood Service cohort from the Wellcome Trust Case Control Consortium. Eight suggestive associations with P<1x10-4 were carried through to in silico replication in 1,292 AAA cases and 30,503 controls. One SNP associated with P<0.05 after Bonferroni correction in the in silico study underwent further replication (706 AAA cases and 1,063 controls from the UK, 507 AAA cases and 199 controls from Denmark and 885 AAA cases and 1,000 controls from New Zealand). Low density lipoprotein receptor (LDLR) rs6511720 A, was significantly associated overall and in three of five individual replication studies. The full study showed an association that reached genome-wide significance (odds ratio 0.76; 95% confidence interval 0.70 to 0.83; P=2.08x10-10).

Conclusions—LDLR rs6511720 is associated with abdominal aortic aneurysm. This finding is consistent with established effects of this variant on coronary artery disease. Shared aetiological pathways with other cardiovascular diseases may present novel opportunities for preventative and therapeutic strategies for AAA.