Familial occurrence of brain arteriovenous malformations: a systematic review

Background: Brain arteriovenous malformations (BAVMs) are thought to be sporadic developmental vascular lesions, but familial occurrence has been described. We compared characteristics of patients with familial BAVMs with those of patients with sporadic BAVMs. Methods: We systematically reviewed the literature on patients with familial BAVMs. Three families that were found in our centre were added. Age, sex distribution and clinical presentation of the identified patients were compared with those in population-based series of patients with sporadic BAVMs. Furthermore, we calculated the difference in mean age at diagnosis of parents and children to study possible anticipation. Results: We identified 53 patients in 25 families with BAVMs. Mean age at diagnosis of patients with familial BAVMs was 27 years (range 9 months-58 years), which was younger than in the reference population (difference between means 8 years, 95% confidence interval (CI) 3-13 years). Patients with familial BAVMs did not differ from the reference populations with respect to sex and mode of presentation. In families with BAVMs in successive generations, the age of the child at diagnosis was younger than the age of the parent (difference between means 22 years, 95% CI 13-30 years), which suggests clinical anticipation. Conclusions: Few patients with familial BAVMs have been described. These patients were diagnosed at younger age than sporadic BAVMs whereas their mode of presentation was similar. Although there are indications of anticipation, it remains as yet unclear whether the described families represent accidental aggregation or indicate true familial occurrence of BAVMs.