Ordering Recommendation

Test for individuals with clinical features of HHT, if sequential testing is desired. Follow with SMAD4 testing if no causative variant is identified in ACVRL1 or ENG.

Mnemonic
HHT FGA
Methodology

Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

28-35 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval

By report

Interpretive Data

Background Information for Hereditary Hemorrhagic Telangiectasia (ACVRL1 and ENG) Sequencing and Deletion/Duplication
Characteristics:
Recurrent nosebleeds, telangiectases (mouth, face, hands, GI tract), and arteriovenous malformations (lung, brain, liver, spine).
Incidence:
1:5,000-10,000
Inheritance:
Autosomal dominant.
Penetrance:
Approaches 100 percent by age 40.
Cause:
Pathogenic variants in ENG, ACVRL1/ALK1, SMAD4, BMP9/GDF2 or other unidentified gene(s).
Genes Tested:
 ENG and ACVRL1
Clinical Sensitivity: Approximately 85 percent
Methodology:
Bidirectional sequencing of the coding regions and intron-exon boundaries of ENG and ACVRL1, the 5' untranslated region of ENG, and a region of ACVRL1 intron 9 encompassing the CT-rich variant hotspot region. Multiplex ligation-dependent probe amplification (MLPA) of the coding regions of ACVRL1 and ENG.
Analytic Sensitivity:
99 percent for sequencing and 90 percent for MLPA.
Analytic Specificity:
99 percent for sequencing and 98 percent for MLPA.
Limitations:
Diagnostic errors can occur due to rare sequence variations. The breakpoints of large deletions/duplication cannot be determined. Regulatory region, intronic mutations, and mutations in genes other than ENG and ACVRL1 will not be detected.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
CPT Codes

81406; 81405; 81479

Components
Component Test Code* Component Chart Name LOINC
0051350 HHT, Sequencing and Deletion/Duplication
2001355 HHT, Seq-Del/Dup - Specimen
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Activin A Receptor, Type II-Like I
  • ACVRL1 Gene; ALK1 Gene
  • Arteriovenous Malformations
  • AVM genetic testing
  • HHT
  • HHT molecular testing
Hereditary Hemorrhagic Telangiectasia (ACVRL1 and ENG) Sequencing and Deletion/Duplication