Hereditary hemorrhagic telangiectasia is characterized by the presence of arteriovenous malformations (AVMs), spontaneous and recurrent nosebleeds (epistaxis), and telangiectases. The age of onset and severity of symptoms vary widely and recurrent epistaxis is the most common first symptom beginning in early adolescence.
| Test Code | 8672 |
| Turnaround Time (TAT) | 14-21 days |
| Number of Genes | 6 |
for all blood relatives of patients who undergo full single gene sequencing or multigene panel testing* at Ambry Genetics and are found to have a pathogenic or likely pathogenic variant. No-cost testing of blood relatives must be completed within 90 days of the original Ambry report date.
Order Now*excludes Secondary Findings and SNP Array tests
Knowing if your patient has a hereditary hemorrhagic telangiectasia can help you determine future risks and guide your medical management recommendations. Key benefits include:
The HHTNext test is designed and validated to be capable of detecting >99% of described mutations in the genes represented on the tests (analytical sensitivity). The clinical sensitivity of the HHTNext test may vary widely according to the specific clinical and family history.
HHTNext is a comprehensive analysis of 6 genes associated with hereditary hemorrhagic telangiectasia. Genomic deoxyribonucleic acid (gDNA) is isolated from the patient’s specimen using standardized methodology and quantified. Sequence enrichment of the targeted coding exons and adjacent intronic nucleotides is carried out by a bait-capture methodology using long biotinylated oligonucleotide probes, and is followed by polymerase chain reaction (PCR) and Next-Generation sequencing (NGS). Additional Sanger sequencing is performed for any regions missing or with insufficient read depth coverage for reliable heterozygous variant detection. Potentially homozygous variants, variants in regions complicated by pseudogene interference, and variant calls not satisfying depth of coverage and variant allele frequency quality thresholds are verified by Sanger sequencing. This assay targets all coding domains, and well into the flanking 5’ and 3’ ends of all the introns and untranslated regions. Gross deletion/duplication analysis is performed for all genes using a custom pipeline based on read-depth from NGS data followed by a confirmatory orthogonal method, as needed. Exon-level resolution may not be achieved for every gene.