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Test Code
1834
Test Name
Spondylometaphyseal Dysplasia With Cone-rod Dystrophy
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
SMDCRD
Description

Spondylometaphyseal dysplasia with cone-rod dystrophy (SMDCRD; MIM 608940) is an autosomal recessive chondrodysplasia caused by mutations in the PCYT1A gene. SMDCRD is one of several spondylometaphyseal dysplasias generally characterized by short stature, flat vertebrae and metaphyseal irregularities. SMDCRD can be distinguished from other spondylometaphyseal dysplasias by the presence of progressive visual impairment of variable age of onset due to pigmentary maculopathy and cone-rod dysfunction.  Additional features of SMDCRD include severe short stature of post natal onset, moderate platyspondyly with anterior projections in infancy and early childhood, rhizomelia, bowing of the long bones of the legs, metaphyseal cupping and flaring, shortened tubular bones, anterior rib cupping and flaring in children, narrowing of the sciatic notches and horizontal acetabuli with spurs.  PCYT1A encodes choline-phosphate cytidylyltransferase A, an enzyme involved in converting phosphocholine into cytidine diphosphate-choline, an intermediate in phosphatidylcholine synthesis.
Testing Schedule
Monday-Friday
Genes
PCYT1A
MIM
608940
Disease Group
Ophthalmology, 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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