Background: Intracranial aneurysms (IA) are dilatations of intracranial arteries that occur most commonly at arterial bifurcations. Unruptured IA are present in approximately 1-2% of the population aged over 30 years of age. Aneurysms are only rarely symptomatic unless they rupture, which typically results in a subarachnoid haemorrhage associated with high morbidity and mortality.
Methods: A large French Canadian (FC) family (Aneu60) was identified which contained 12 affected individuals with intracranial aneurysms. Nine of the affected patients and three unaffected individuals were sent for an 8 cM genome-wide scan. Multipoint and two-point methods were used to analyse the scan data by using a dominant parametric model.
Results: We identified an IA susceptibility locus (ANIB4) located on chromosome 5p15.2-14.3. The locus was found by genome-wide linkage analysis and follow up analyses provided a maximum multipoint LOD score of 3.57 over the region. An identical haplotype segment of 7.2 Mb was found in a second FC pedigree and contributes to the refinement of the candidate gene interval.
Conclusions: Our results indicate that there is a major gene locus on chromosome 5p.