

Here I present: “Hemorrhagic Telangiectasia”, Victor McKusick, Mendelian Inheritance in Man’, 1966. (ENG) 出血性毛細血管擴張症。 icd10=I78.0
Genomic coordinate (9:127,815,016 human ENG) & (2:32,536,606 mouse Eng).
Cytoband (9q34.11 human ENG) & (2qE mouse Eng).
INTRODUCTION.
Hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular dysplasia leading to telangiectases (dilated blood vessels) and arteriovenous malformations (AVM) of skin, mucosa, and viscera. Epistaxis and gastrointestinal bleeding are frequent complications of mucosal involvement. Visceral involvement includes that of the lung, liver, and brain.
Hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder with fragile, dilated blood vessels (telangiectasias) and larger arteriovenous malformations (AVM)
Diagnostic Criteria:
1. Recurrent spontaneous nosebleeds.
2. Multiple mucocutaneous telangiectasias (lips, tongue, face, fingers).
3. Visceral AVM (lung, brain, liver, GI tract).
4. First-degree relative with HHT.
Genetics:- ENG (Endoglin).
Pathophysiology:
Defective TGF-beta/BMP endothelial signaling.
→abnormal vascular remodeling.
→ fragile vessels without normal capillary beds.
Symptoms:
-Nosebleeds
– GI bleeding
– Iron-deficiency anemia
– Pulmonary AVM (stroke risk, hypoxemia)
– Cerebral AVM (hemorrhage risk)
– Hepatic AVM (high-output heart failure).
There is evidence that hemorrhagic telangiectasia is caused by mutation in the endoglin (ENG) gene in humans encoded on genomic coordinate 9:127,815,016 and cytoband 9q34.11.



