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Symptomatic children with hereditary hemorrhagic telangiectasia: a pediatric center experience
Meir Mei-Zahav1, Michelle Letarte, Marie E Faughnan
1Division of Respiratory Medicine, Department of Pediatrics, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada. meirmeizahav@hotmail.com
Insights
Symptomatic children with hereditary hemorrhagic telangiectasia (HHT) often have visceral arteriovenous malformations (AVMs) and telangiectases, leading to serious complications. Genetic testing in these HHT patients may reveal complex mutations or new genes.
Area of Science:
- Pediatric genetics
- Vascular malformations
- Rare disease research
Background:
- Hereditary hemorrhagic telangiectasia (HHT) is a rare genetic disorder.
- Clinical and genetic profiles of affected children are not well-defined.
Purpose of the Study:
- To evaluate clinical manifestations and genetic factors in symptomatic children with HHT.
- To determine the prevalence of visceral arteriovenous malformations (AVMs) and genetic mutations.
Main Methods:
- Cross-sectional study of 14 symptomatic children with HHT.
- Screening for visceral AVMs and molecular genetic testing.
- Analysis of epistaxis, telangiectases, and AVM prevalence.
Main Results:
- Seven children had cardiorespiratory symptoms due to pulmonary AVMs; three had neurological symptoms from spinal or cerebral AVMs.
- One asymptomatic child had a cerebral AVM; two had pulmonary AVMs.
- Genetic mutations (ENG or ACVRL1) were identified in 5 children; no mutation was found in 2 children.
Conclusions:
- Visceral AVMs and mucosal telangiectases are common in pediatric HHT and can cause severe events.
- Undetected mutations suggest complex genetic factors or novel genes in HHT.
Objective:
To assess the clinical and genetic characteristics of symptomatic children with hereditary hemorrhagic telangiectasia (HHT).
Design:
Cross-sectional study.
Setting:
The HHT clinics in Toronto.
Participants:
All children with symptomatic HHT treated from April 1, 1996, through December 31, 2002.
Interventions:
Participants were screened for visceral arteriovenous malformations (AVMs). Molecular testing was performed in the children or their affected family members.
Main Outcome Measures:
Prevalence of epistaxis, telangiectases, pulmonary and cerebral AVMs, and genetic characteristics.
Results:
Fourteen children presented with manifestations of HHT. Seven had cardiorespiratory symptoms related to pulmonary AVMs. Three had neurological symptoms secondary to bleeding from spinal or cerebral AVMs. Two were referred because of skin telangiectases and 2, because of multiple episodes of epistaxis. Screening results revealed a cerebral AVM in 1 of 11 neurologically asymptomatic children. Of the children without respiratory symptoms, 1 was diagnosed as having definite and 1, suspected pulmonary AVMs. Four children with pulmonary AVMs carried an endoglin gene mutation (HHT type 1), and 1 carried an activin receptor-like kinase 1 gene mutation (HHT type 2). The 2 children with spinal AVMs belong to the same HHT type 2 family. No mutation was found in 1 child with pulmonary and 1 with cerebral AVMs.
Conclusions:
Visceral AVMs and mucosal telangiectases are present in children with HHT and can lead to life-threatening events. Failure to identify a disease-associated mutation for each child suggests complex mutations or novel HHT genes.
