Cancer-type somatic mutations in saccular cerebral aneurysms.

Intracranial aneurysms (IAs) are a major cause of subarachnoidal hemorrhage (SAH) which can have a significant morbidity and mortality. The processes underlying the aneurysm development remains unclear. We performed whole exome sequencing of DNA derived from 20 saccular cerebral aneurysms of 20 patients, followed by somatic variant calling. Eleven (55%) of the 20 patients had detectable nonsynonymous somatic mutations and in total, 48 mutations were detected in the aneurysm samples. The mutations were highly enriched in cancer-related genes and 77% were predictably deleterious. A p.Tyr562Asp somatic mutation was detected in the PDGFRB gene; somatic mutations at the same codon have been reported in fusiform cerebral aneurysms. These results widen the concept on the role of somatic mutations in cerebral aneurysms, indicating their possible role in the more common saccular aneurysm, similarly to the rarer fusiform aneurysm.