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Test Code
1566
Test Name
Juvenile Polyposis/hereditary Hemorrhagic Telangiectasia Syndrome
CPT Codes
81405, 81406
Expected Turnaround Time
Typically 2 to 4 weeks from receipt of a sample in the laboratory. All cases involving ongoing pregnancies will be expedited.
Clinical Utility
Genetic analysis to provide a molecular diagnosis of this disorder. Recommended for individuals with a personal and/or family history of this disorder to ensure appropriate treatment and establish recurrence risk for family members.
Specimen and Container Info

Non-Prenatal Specimens

Preferred/Alternate

Specimen Type

Containers

Volume

Preferred Specimen Type

Whole Blood

Lavender Top (EDTA)

3 mL

Alternate Specimen Type

Genomic DNA

1.5 mL Tube

3 µg (at a concentration of at least 30 ng/µl), preferably in TE solution.

Alternate Specimen Type

Fibroblasts

T-25 Flasks

2 confluent T-25 flasks, filled to capacity

Alternate Specimen Type

Saliva (Whole blood is recommended for CNV)

DNA Self-Collection Kit or Oragene Saliva Collection Kit for Young Children

Follow kit instructions (www.dnagenotek.com)

Prenatal Specimens

Either specimen type below is acceptable.

Specimen Type

Containers

Volume

Cultured cells

T-25 Flasks

2 confluent T-25 flasks derived from amnio or CVS samples.

Genomic DNA

1.5 mL Tube

3 µg (at a concentration of at least 30 ng/µl), preferably in TE solution.

NOTE: For specimens from outside of North America, the preferred specimen type is Genomic DNA. HNL Genomics does not recommend shipping whole blood or cultured cells from any location other than the United States, Canada, or Mexico.
Transport Instructions
  • Transport at room temperature within 24 hours.
  • If the specimen cannot be transported to the lab within 24 hours, refrigerate for up to 72 hours.
  • Do not freeze or expose to extreme temperatures, refrigerate for up to 72 hours if cannot be transported to lab within 24 hours. 
Stability Requirements

Room Temperature

24 hours

Refrigerated

72 hours
Causes for Rejection
  • Improperly labeled specimen (minimum of two patient identifiers)
  • Inappropriate specimen type
  • Incomplete or incorrect test request form
  • Insufficient volume
  • Specimen has leaked in transit
  • Specimen without a test order
Methodology
Next Generation Sequencing and Copy Number Variation Analysis
Performing Location
Genomics - Snowdrift
Alternate Names
JPHT
Description

Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome (JPHT; MIM 175050) is an autosomal dominant disorder with the combined phenotypic features of juvenile polyposis syndrome and hereditary hemorrhagic telangiectasia.  JPHT is caused by loss of function mutations in the SMAD4 gene. SMAD4 encodes a protein with a critical role in transforming growth factor-beta and bone morphogenic protein signal transduction.   JPHT  is characterized by multiple juvenile polyps throughout the stomach and bowel, telangiectases of the skin, oral and nasal mucosa, and arteriovenous malformations (AVM) of the viscera and brain.  Individuals with this disorder are at an increased risk of gastrointestinal cancer at a relatively young age.  Other clinical findings include epistaxis, oral and gastrointestinal bleeds, hepatic telangiectasia with arterial-portal shunting, cavernous hemangiomas, intracranial abscess, intracranial bleeds, and stroke.  Digital clubbing and hypertrophic osteoarthropathy have also been described.   Rarely, individuals have been reported with cardiac findings or aortic dilation.
Testing Schedule
Monday-Friday
Genes
SMAD4
MIM
175050
Disease Group
Cardiovascular Disorders, Connective Tissue, Skin
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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