GTR Home > Tests > Hereditary Hemorrhagic Telangiectasia


Test order codeHelp: Available through LabCorp for U.S. Customers: HHT Proband = 4800

Test name


Hereditary Hemorrhagic Telangiectasia (HHT)

Purpose of the test


This is a clinical test intended for Help: Diagnosis, Mutation Confirmation, Pre-symptomatic, Predictive, Risk Assessment, Screening, Therapeutic management



5 conditions tested. Click Indication tab for more information.


Molecular Genetics
DDeletion/duplication analysis
Multiplex Ligation-dependent Probe Amplification (MLPA)
  • Applied Biosystems 3730 capillary sequencing instrument
RRNA analysis
RT-PCR and cDNA sequencing
CSequence analysis of the entire coding region
Bi-directional Sanger Sequence Analysis
  • Applied Biosystems 3730 capillary sequencing instrument

Summary of what is tested

3 genes and variants. Click Methodology tab for more information.


Clinical validity


The test detects a mutation in over 89.1% of patients meeting at least three CuraƧao criteria. At least two other chromosomal regions are expected to be involved in HHT. When a test is developed for these regions we will re-test all samples with no mutation found and re-issue reports with updated information. It is very important that the family member with clearest clinical diagnosis of HHT is tested first to find the causative mutation in the family.

  • Hereditary haemorrhagic telangiectasia: mutation detection, test sensitivity and novel mutations. - PubMed ID: 16690726

Clinical utility


Not provided

Testing strategy


We use MLPA for exon copy number analysis, and sequence analysis of all exons and nearby flanking intronic regions, for the ACVRL1 and ENG genes until a causative mutation is found. The 5' UTR region of ENG is included in sequencing analysis. If no mutation is found we also sequence exons 8,9,10 and 11 of SMAD4.

How to order


Canada: E-mail that a sample is being sent. Download, fill in, and include HHT required forms (available at Prepare the HHT Sample as per the guidelines provided. Ship the HHT Sample to us for testing. U.S.A.: Download, fill in and include HHT required forms (available at and provide Lab Corp TRF 1900 Comprehensive Genetics form with appropriate ICD10 code. Call Impact Genetics for additional info
Order URL Help:

Test services

  • Clinical Testing/Confirmation of Mutations Identified Previously
  • Confirmation of research findings
  • Data Storage and Backup
  • Maternal cell contamination study (MCC)
  • Result interpretation
  • Custom Prenatal Testing
  • Custom mutation-specific/Carrier testing, comments

Suggested reading

  • Shovlin et al., 2000
    Diagnostic criteria for hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome).

Practice guidelines

IMPORTANT NOTE: NIH does not independently verify information submitted to the GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in the GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

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