• Test Code:
    1285
  • Department:
  • Test Synonyms:
    Neuromuscular disordersDystroglycanopathiesCHKBCOL6A1COL6A2COL6A3DAG1DPM1DPM3FKRPFKTN ISPDITGA7LAMA2LARGELMNAPOMGNT1POMT1POMT2RYR1SEPN1TCAP
  • CPT Code(s):
    81408
Background:

Neuromuscular disorders are a group of heterogeneous conditions affecting the nervous system that controls muscle movements. This neuronal damage in turn causes degradation of the affected muscular tissue causing weakness and loss of muscle tone.  Congenital muscular dystrophies have onsets ranging from birth to early infancy. Affected children may present with progressive muscle weakness, delayed motor development, joint contractures and spinal defects. This NGS tests for congenital muscular dystrophies including the following subtypes: defects of structural protein, defects of glycosylation, defects of proteins in endoplasmic reticulum, defects of nuclear envelope proteins, and dystroglycanopathies. Many of the congenital muscular dystrophies are autosomal recessive, however collagen VI deficient and LMNA-associated muscular dystrophies can be autosomal dominant.

Reasons for Referral:

  • Abnormal serum creatine kinase levels
  • Muscle degradation
  • Abnormal electromyography (EMG)
  • Abnormal nerve conduction studies (NCS)
  • Positive family history (targeted testing is available if familial mutation is known).
  • Carrier testing

Methodology:

This test has two components:

Component 1: Next generation sequencing will analyze the exons or coding regions of 20 Congenital Muscular Dystrophy-associated genes using Illumina NextSeq 500 technology and preparing samples using hybridization probes to enrich exonic regions. Promoter, intronic, etc. regions are not assessed here but may contain variants that impact gene function.

Component 2: A customized CytoSure “exon-centric” array (Oxford Gene Technology) will be used to detect deletions and duplications. The targeted array has enhanced probes targeted to the exonic regions of the of 20 Congenital Muscular Dystrophy-associated genes. The arrays will be run using Agilent SureScan technology. This array is an ideal complement to the next generation sequencing approach to provide a comprehensive mutation spectrum analysis for Congenital Muscular Dystrophy.

Congenital Muscular Dystrophy (20 genes): CHKB, COL6A1, COL6A2, COL6A3, DAG1, DPM1, DPM3, FKRP, FKTN, ISPD, ITGA7, LAMA2, LARGE, LMNA, POMGNT1, POMT1, POMT2, RYR1, SEPN1, TCAP 

Specimen Requirements:

Blood:  EDTA or ACD (Solution A or B):

  • Adult: 5 mL
  • Child: 5 mL
  • Infant: 2-3 mL

DNA: 10µg at a minimum of 60-100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)

For routine testing of blood, saliva and buccal swabs, KDL does NOT accept samples from patients within two (2) weeks of a packed cell/platelet transfusion or within four (4) weeks of a whole blood transfusion.  For extraordinary circumstances, where testing must be performed outside of the above windows, please contact our lab.

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information, including ethnicity, clinical history, and family history.

Test Performed (Days):

Weekly

Turn Around Time:

8 weeks

Shipment Sensitivity Requirements:

  • Package and ship specimen to remain cold, but not frozen. 
  • Ship via overnight express, using the FedEx priority overnight label provided. 
  • Contact Client Services for shipping kits and instructions at (855) 535-1522.

References:

  1. GeneReviews: Congenital myopathies and congenital muscular dystrophies.

     Curr Opin Neurol. 2001 Oct;14(5):575-82. http://www.ncbi.nlm.nih.gov/pubmed/11562568

  2. GeneReviews: Congenital Muscular Dystrophy Overview http://www.ncbi.nlm.nih.gov/books/NBK1291/

Additional Info:

The Knight Cancer Institute at Oregon Health & Science University is a pioneer in the field of precision cancer medicine. The institute's director, Brian Druker, M.D., helped prove it was possible to shut down just the cells that enable cancer to grow. This breakthrough has made once-fatal forms of the disease manageable and transformed how cancer is treated. The OHSU Knight Cancer Institute is the only National Cancer Institute-designated Cancer Center between Sacramento and Seattle – an honor earned only by the nation's top cancer centers. It is headquarters for one of the National Cancer Institute's largest research collaboratives, SWOG, in addition to offering the latest treatments and technologies as well as hundreds of research studies and clinical trials.

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