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Test Code
1655
Test Name
Spondyloepimetaphyseal Dysplasia With Joint Laxity Type 2
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
SEMDJL2
Description

Spondyloepimetaphyseal dysplasia with joint laxity type 1, with or without fractures (SEMDJL1; MIM 271640) and spondyloepimetaphyseal dysplasia with joint laxity type 2 (SEMDJL2; MIM 603546) are clinically related disorders. Common clinical findings include spondyloepimetaphyseal dysplasia, short stature, ligamentous laxity with joint dislocations, midface hypoplasia, and kyphoscoliosis. Patients with SEMDJL1, unlike the patients with SEMDJL2, have progressive severe kyphoscoliosis and respiratory compromise leading to early death. These patients may also have club foot, cleft palate, congenital heart disease, blue sclerae and fractures. Patients with SEMDJL2 typically have slender metacarpals and phalanges and the progressive degeneration of carpal bones. These findings are seen in only in older children and young adults. Laryngotracheomalacia is also a common finding in SEMDJL2. The primary differential diagnoses include Larsen syndrome (LRS1; MIM 150250), various types of Ehlers-Danlos syndrome,  pseudoachondroplasia (PSACH; MIM 177170) and spondyloepiphyseal dysplasia congenita (SEDC; MIM 183900). SEMDJL1 is an autosomal recessive disorder caused by mutations in the B3GALT6 gene, which codes for beta-1,3-galactosyltransferase 6. SEMDJL2 is an autosomal dominant disorder caused by mutations in the KIF22 gene encoding kinesin like protein 22.

Panel genes are also offered as individual sequencing and deletion/duplication tests, unless otherwise indicated.
Testing Schedule
Monday-Friday
Genes
KIF22
MIM
603546
Disease Group
Skeletal Disorders
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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