<i>PCNT</i> point mutations and familial intracranial aneurysms.

Abstract

To identify novel genes involved in the etiology of intracranial aneurysms (IAs) or subarachnoid hemorrhages (SAHs) using whole-exome sequencing. We performed whole-exome sequencing in 13 individuals from 3 families with an autosomal dominant IA/SAH inheritance pattern to look for candidate genes for disease. In addition, we sequenced <i>PCNT</i> exon 38 in a further 161 idiopathic patients with IA/SAH to find additional carriers of potential pathogenic variants. We identified 2 different variants in exon 38 from the <i>PCNT</i> gene shared between affected members from 2 different families with either IA or SAH (p.R2728C and p.V2811L). One hundred sixty-four samples with either SAH or IA were Sanger sequenced for the <i>PCNT</i> exon 38. Five additional missense mutations were identified. We also found a second p.V2811L carrier in a family with a history of neurovascular diseases. The <i>PCNT</i> gene encodes a protein that is involved in the process of microtubule nucleation and organization in interphase and mitosis. Biallelic loss-of-function mutations in <i>PCNT</i> cause a form of primordial dwarfism (microcephalic osteodysplastic primordial dwarfism type II), and ≈50% of these patients will develop neurovascular abnormalities, including IAs and SAHs. In addition, a complete <i>Pcnt</i> knockout mouse model (<i>Pcnt</i> ^-/-) published previously showed general vascular abnormalities, including intracranial hemorrhage. The variants in our families lie in the highly conserved PCNT protein-protein interaction domain, making <i>PCNT</i> a highly plausible candidate gene in cerebrovascular disease.