Screening for pulmonary and cerebral arteriovenous malformations in children with hereditary haemorrhagic telangiectasia

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterised by vascular dysplasia complicated by visceral arteriovenous malformations (AVMs). To date, the diagnostic yield of screening procedures for pulmonary and cerebral AVMs in children with definite or potential HHT is not well defined. The aim of the present study was to prospectively evaluate the diagnostic yield of a screening protocol for pulmonary and cerebral AVMs in children with either a definite or potential HHT diagnosis. All children referred for evaluation for HHT between 1996 and 2008 were included in the present analysis. Screening tests for AVMs included chest computed tomography and brain magnetic resonance imaging. 61 children with a definite clinical and/or genetic diagnosis of HHT were asymptomatic for visceral AVMs at their first baseline assessment (mean +/- SD age 8.7 +/- 4.7 yrs; range 0-17.0 yrs). Of these, 15 (25%) had pulmonary and/or cerebral AVMs diagnosed on initial screening tests. Pulmonary AVMs predominated in paediatric HHT patients (14 out of 15 patients) and were found in eight children aged < 10 yrs. 55 children had a potential HHT diagnosis as they fulfilled only one or two HHT clinical diagnostic criteria and did not have a confirmatory genetic diagnosis (age 10.9 +/- 4.8 yrs; range 0-17.9 yrs). None of these children had pulmonary or cerebral AVMs on initial screening tests. The present data suggest that children with a definite HHT diagnosis have a high frequency of pulmonary AVMs; even when clinically asymptomatic. In contrast, no AVMs; were observed in children not fulfilling HHT diagnostic criteria. Genetic testing appears to be useful in defining an at-risk group for pulmonary AVMs in childhood.