Panel Description

Hereditary Hemorrhagic Telangiectasia
The Hereditary Hemorrhagic Telangiectasia Panel examines 4 genes associated with hereditary hemorrhagic telangiectasia (HHT).

Patients with a personal and/or family history suggestive of HHT. HHT is a disorder that primarily affects the blood vessels. Symptoms of affected individuals can include, but are not limited to, nosebleeds, spider veins (telangiectasias) particularly on the face, and hemorrhages in the brain, liver, lungs, or other organs.

Patients identified with HHT can benefit from increased surveillance and preventative steps to better manage their symptoms and risks. Medical intervention can include laser ablation and/or surgical resection of bleeding sites, lifestyle changes, and iron supplementation for anemia. Also, your patient’s family members can be tested to help define their risk. If a pathogenic variant is identified in your patient, close relatives (children, siblings, parents) could have as high as a 50% risk to also be at increased risk. In some cases, screening should begin in childhood.

Test Description

  • Sequencing
  • Del/Dup
  • Rush / STAT
  • Exclude VUS
  • MCC
  • Duo/Trio
2.9 – 3.857142857142857 weeks
Call for details
ACVRL1, ENG, EPHB4, GDF2, RASA1, SMAD4 ( 6 genes )
96% at 20x
Blood (two 4ml EDTA tubes, lavender top) or Extracted DNA (3ug in EB buffer) or Buccal Swab or Saliva (kits available upon request)
All sequencing technologies have limitations. This analysis is performed by Next Generation Sequencing (NGS) and is designed to examine coding regions and splicing junctions. Although next generation sequencing technologies and our bioinformatics analysis significantly reduce the contribution of pseudogene sequences or other highly-homologous sequences, these may still occasionally interfere with the technical ability of the assay to identify pathogenic variant alleles in both sequencing and deletion/duplication analyses. Sanger sequencing is used to confirm variants with low quality scores and to meet coverage standards. If ordered, deletion/duplication analysis can identify alterations of genomic regions which include one whole gene (buccal swab specimens and whole blood specimens) and are two or more contiguous exons in size (whole blood specimens only); single exon deletions or duplications may occasionally be identified, but are not routinely detected by this test. Identified putative deletions or duplications are confirmed by an orthogonal method (qPCR or MLPA). This assay will not detect certain types of genomic alterations which may cause disease such as, but not limited to, translocations or inversions, repeat expansions (eg. trinucleotides or hexanucleotides), alterations in most regulatory regions (promoter regions) or deep intronic regions (greater than 20bp from an exon). This assay is not designed or validated for the detection of somatic mosaicism or somatic mutations.


 – McDonald, J., Pyeritz, R.E. Hereditary Hemorrhagic Telangiectasia. 2000 Jun 26 [Updated 2017 Feb 2]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle (1993-2017)