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Duchenne/Becker Muscular Dystrophy (DMD/BMD) by Multiplex Ligation-dependent Probe Amplification (MLPA) – Saskatoon

Discipline

Genetics and Genomics

Overview

Description

Ordering recommendations

  • Duchenne/Becker muscular dystrophy is a X-linked neuromuscular disease that affects cardiac, skeletal and smooth muscle, and neurons. Approximately 70-80% of DMD/BMD patients are associated with deletions or duplications involving one or more exons of the dystrophin (DMD) gene. Small insertions, deletions, and point mutations in the DMD gene account for the remainder of disease-causing mutations in DMD/BMD. Please note that MLPA only detects CNV (deletions and duplications) in DMD; for both SNV and CNV detection, please request NGS testing.
  • Ordering of this test is restricted to Medical Genetics and physicians who have been granted approval by Medical Genetics.
  • DNA may also be extracted from peripheral blood at RRPL and sent to RUH Genomics Lab for testing.

Ordering requirements

Specimen Information

Specimen types accepted

  • Peripheral blood/whole blood
  • Genomic DNA extracted at RUH Genomics Lab or RRPL

Specimen collection container

Collection procedure

  • Invert tube several times to mix
  • Specimen must be accompanied by a completed test requisition, signed by physician
  • Failure to include relevant patient information may result in test results being delayed or discontinued

Required volume

  • Optimal volume: 4-7 mL
  • Minimum volume for adult: 2 mL blood
  • Minimum volume for Pediatric patient: 1 mL of peripheral blood or cord blood

(Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory/reflex testing. In some situations, a minimum volume may require a second collection.)

Transport and stability

  • Ship specimens at ambient temperature
  • Specimens may be stored at 2-8°C

Rejection criteria

Testing Information

Clinical information

Patient history

  • Refer to requisition to fill out all relevant patient’s clinical symptoms that apply.   

Performance

Methodology

  • MLPA uses specific probes to hybridize to the target sequence and are ligated by ligase enzyme. Ligated probes are then amplified by a universal pair of fluorescently-tagged PCR primers. The resulting PCR amplicons are separated and quantified by capillary electrophoresis, then compared to internal reference fragments and reference samples to determine copy number variants.

Days/times performed

  • Specimens accepted Monday to Friday, 8:00 a.m. to 5:00 p.m., at the RUH Genomics Laboratory

Maximum laboratory time

Results reporting

  • Turnaround time: 4-6 weeks

Specimen retention time

  • DNA banking specimens are stored and retained at RRPL as their banking policy.

Last Updated: March 28, 2024