Saccular Intracranial Aneurysms in Children When Both Parents Are Sporadic or Familial Carriers of Saccular Intracranial Aneurysms

<b><i>Background and purpose:</i></b> To study the penetrance of saccular intracranial aneurysm (IA) disease in children when both parents carry the disease. <b><i>Patients and methods:</i></b> The Kuopio IA Patient and Family Database includes all 4,411 IA patients admitted to the Kuopio University Hospital from its defined Eastern Finnish catchment population since 1980. We fused IA database with hospital diagnoses for IA patients and their 46,021 relatives from a national registry to identify couples concordant for IA disease. Penetrance of IA disease and hypertension were studied in these families. <b><i>Results:</i></b> A total of 3,659 IA patients had 1 or more children. In total, 18 couples concordant for the IA disease with a total of 48 children, all born healthy, were identified. Hypertension was diagnosed in 23 (64%) of the 36 parents, and 7 of the 12 sporadic-sporadic couples were concordant for hypertension. Six sporadic-sporadic couples were concordant for subarachnoid haemorrhage (SAH). None of the 24 children to the 12 sporadic-sporadic couples had been diagnosed with SAH or IA disease. Instead, 11 (46%) of the 24 children to the 6 familial-sporadic couples had a diagnosed with SAH or IA disease. <b><i>Conclusions:</i></b> Couples concordant for IA disease are uncommon but not exceedingly rare. Biparental sporadic exposure does not seem to increase the risk of a clinically diagnosed IA disease or SAH in the offspring. IAs were common in the children with biparental sporadic-familial exposure.