Hereditary Hemorrhagic Telangiectasia Variant Curation Expert Panel

Pathogenic germline variants in ACVRL1, ENG, and SMAD4 are associated with hereditary hemorrhagic telangiectasia (HHT, MIM: 600376, 187300) and juvenile polyposis syndrome/HHT (JPS/HHT, MIM: 175050). HHT is an autosomal dominant vascular dysplasia characterized by small vascular lesions (telangiectases) and larger vascular legions (arteriovenous malformations (AVMs)) in characteristic locations (telangiectases in the oral and nasal mucosa, lips, fingers, upper intestinal tract; AVMs in the lungs, liver and brain). This expert panel will provide assessment regarding the pathogenicity of variants in ACVRL1, ENG, and SMAD4 with respect to HHT disease. Specifically, we will develop a set of HHT rule specifications of the ACMG/AMP guidelines with individual gene specifications where needed. We will first focus our efforts on curating variants that are currently in ClinVar, and then we will expand our efforts to curating variants from other HHT databases and submit those to ClinVar.

Expert Status - In progress

Step 1
Step 2
Step 3
Step 4
Define Group
Develop Classification Rules
In progress
Pilot Rules
Expert Panel Approval


Pinar Bayrak-Toydemir, MD, PhD, FACMG

Jamie McDonald, MS, LCGC


Please contact a coordinator if you have questions.

Desiree DeMille, PhD


Membership in this committee spans many fields, including genetics, medical, academia, and industry. [View Members]
For more information, please contact:

Desiree DeMille, PhD


A systematic process of evaluating evidence to classify a genomic variant on a spectrum from pathogenic to benign with respect to a particular disease and inheritance pattern.