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12 Cards in this Set
- Front
- Back
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Clinical HHT
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Synonym
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Osler-Weber-Rendu
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Inheritance
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Autosomal dominant HHT1: endoglin gene on 9q33 34 Autosomal dominant HHT2: ALK1 gene on chromosome 12
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Prenatal
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DNA linkage analysis or mutation detection
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Incidence
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1 2:100,000; M=F; all races, most common in whites
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Age at Presentation
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Early childhood to young adulthood with epistaxis in 50% of patients Cutaneous, gastrointestinal telangiectasias usually begins in the third to fourth decade
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Pathogenesis
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HHTI: Mutation in endoglin gene on chromosome 9q33 34, a transforming growth factor (TGF) p binding protein on endothelial cells essential for angiogenesis HHT2: Mutation on chromosome 12 encoding for activin receptor like kinase I (ALKI) expressed on endothelial cells
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Clinical
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Skin
Telangiectasias on face, palms, soles, subungual region Mucous Membranes Telangiectasias on vermillion, oral and nasopharyngeal mucosa, conjunctiva Ear Nose Throat Epistaxis recurrent in more than 80% of patients Gastrointestinal Telangiectasias with secondary hemorrhage; hepatic AVMs Pulmonary Arteriovenous fistulas complicated by hemorrhage, cerebral abscesses |
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D/Dx
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CREST syndrome Generalized essential telangiectasia Ataxia telangiectasia (p. Il 2) Fabry disease (p. 306)
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Lab
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Chest x ray screen, follow up MRI if positive
Complete blood count (CBC) Guaiac stool screen Endoscopy if symptomatic |
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Management
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Referral to otolaryngologist cautery, packing, estrogen, septal dermoplasty for recurrent epistaxis; transfusions, iron supplementation
Referral to gastroenterologist if symptomatic Referral to thoracic surgeon excision, embolization of A V fistula Referral to dermatologist pulsed dye laser for telangiectasias |
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Prognosis
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HHT1 families have increased incidence of pulmonary A V fistulaes
HHT2 families with increase in hepatic AVMs |
