Hereditary Hemorrhagic Telangiectasia Sequence, Deletion/Duplication
Label Mnemonic: HHTSDD
Epic code: LAB7337
Downtime form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
Commercial Mail-out Laboratory
5231 RCP
Whole Blood
Collection Medium:
Lavender top tube 3 mL (EDTA)
Alternate Collection Media:
Pink top tube 6 mL (K2-EDTA) or Yellow top tube 8.5 mL (ACD solution A)
Preferred Minimum: 3.0 mL whole blood
Absolute Minimum: 2.0 ml whole blood
Turn Around Time:
Within 35 days
Reference Range:
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, 

Incidence: 1:5,000-10,000

Inheritance: Autosomal dominant.

Penetrance: Approaches 100 percent by age 40.

Cause: Mutations in endoglin (ENG), activin A receptor type II-like 1 
(ACVRL1 or ALK1),  SMAD4 or other unidentified gene(s).

Clinical Sensitivity: Approximately 85 percent

Analytic Sensitivity: 99 percent for sequencing and 90 percent for 

Analytic Specificity: 99 percent for sequencing and 98 percent for 
This mailout test requires pathologist approval for orders during inpatient encounters. Mailouts staff will not process order without approval. The pathologist covering mailouts approval can be reached at pager #5379. If approval is given, the name of the pathologist can be selected in the drop-down menu to the right of the approval warning in Epic when ordering the test.

Please print, complete and submit the following forms to the lab, with the specimen and the A-1a Miscellaneous Request:

HHT Testing Consent Form (Full Gene)

   and the

Patient History for HHT from ARUP Laboratories.
Test 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.
Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
CPT Code:
81406 (ENG), 81405 (ENG), 81479 x2