Familial Intracranial Aneurysm in Newfoundland: Clinical and Genetic Analysis

Abstract

ABSTRACT:Objective:Intracranial aneurysm (IA) is an expansion of the weakened arterial wall that is often asymptomatic until rupture, resulting in subarachnoid hemorrhage. Here we describe the high prevalence of familial IA in a cohort of Newfoundland ancestry. We began to investigate the genetic etiology of IA in affected family members, as the inheritance of this disease is poorly understood.Methods:Whole exome sequencing was completed for a cohort of 12 affected individuals from two multiplex families with a strong family history of IA. A filtering strategy was implemented to identify rare, shared variants. Filtered variants were prioritized based on validation by Sanger sequencing and segregation within the families.Results:In family R1352, six variants passed filtering; while in family R1256, 68 variants remained, so further filtering was pursued. Following validation by Sanger sequencing, top candidates were investigated in a set of population controls, namely,C4orf6c.A1G (p.M1V) andSPDYE4c.C103T (p.P35S). Neither was detected in 100 Newfoundland control samples.Conclusion:Rare and potentially deleterious variants were identified in both families, though incomplete segregation was identified for all filtered variants. Alternate methods of variant prioritization and broader considerations regarding the interplay of genetic and environmental factors are necessary in future studies of this disease.

Genetics of Intracranial Aneurysms

“…46 Three other WES studies did not result in the identification of risk genes for IA. [54][55][56] None of the variants identified in family studies have been found in other populations. Additional rare, damaging, variants in ANGPTL6 57 and low-frequency variants in PCNT, RNF213, and THSD1 were identified in other populations, 58 but evidence for causality of these additional variants is limited.…”

Whole Exome Sequencing in Patients with Phenotypically Associated Familial Intracranial Aneurysm

“…GBA and C9orf92 genes have been reported as susceptible genes associated with brain aneurysm in the GWAS catalog, and the remaining genes were reported to be associated with aneurysm or vascular/connective tissue disorders in the OMIM. The genes found in recent NGS studies were not identified in this study [ 8 20 21 22 23 24 25 26 27 ].…”