Test Directory

Test Code
2332
Test Name
Leri-Weill Dyschondrosteosis
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
LWD; LMD
Description

Leri-Weill dyschondrosteosis (LWD; MIM 127300) is an autosomal (pseudoautosomal) dominant and Langer mesomelic dysplasia (LMD; MIM 249700) is an autosomal (pseudoautosomal) recessive disorder caused by mutations in the pseudoautosomal genes, SHOX or SHOXY. Causative mutations include gene deletions, point mutations in the coding sequences or large deletions in the non-coding regulatory elements. LWD is characterized by disproportionate short stature, mesomelia, Madelung deformity of the wrist, and tibial bowing. It is usually more severe in females than in males, presumably due to the higher estrogen levels. LMD and LWD are clinically similar, but LMD is more severe. LMD clinical findings include severe limb aplasia, severe hypoplasia of the ulna and fibula, thickened and curved radius and tibia, and hypoplasia of the mandible. In addition, is it estimated that approximately 2-5% of individuals with idiopathic short stature (ISS; MIM 300582) have defects in SHOX or its enhancers.

Testing Schedule
Monday-Friday
Genes
SHOX
Disease Group
Skeletal Disorders