Test Directory

Test Code
1738
Test Name
Glomuvenous Venous Malformations Malformations And Cutaneomucosal NGS Panel
CPT Codes
81479
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
  • GVM
  • VMCM
Description

Glomuvenous malformations (GVM) and Cutaneomucosal venous malformations (VMCM) - Glomuvenous malformations (GVM; MIM 138000) are a type of vascular malformation mainly involving the skin and subcutis of the extremities. GVM are often present at birth and slowly expand. Typically they are nodular, multifocal hyperkeratotic lesions with a cobble stone appearance. They are often painful on palpation, pink to dark blue in color and cannot be emptied on compression. These features distinguish GVM from typical venous malformation.  Histologically, GVM are characterized by distended vascular channels surrounded by mural glomus cells. Glomus cells are considered to be abnormally differentiated vascular smooth muscle cells. GVM are caused by loss of function mutations in the glomulin (GLMN) gene. Although inheritance is considered to be autosomal dominant, some evidence suggests that a 'second hit' somatic mutation (paradominant inheritance) is required for the lesions to develop.

Cutaneomucosal venous malformations (VMCM; MIM 600195) are inherited in autosomal dominant manner with incomplete penetrance. VMCM are characterized by small, soft, blue colored, multifocal venous malformations that can be seen at birth. Unlike the GVM, VMCM can be emptied by external pressure. The VMCM can involve skin and oral mucosa. VMCM are caused by mutations in the endothelial cell tyrosine kinase receptor gene (TEK, formerly known as TIE2).

Testing Schedule
Monday-Friday
Genes
GLMN, TEK
MIM
138000, 600195
Disease Group
Cardiovascular Disorders, Skin