Lab Test

Mitochondrial DNA (MELAS)

NARP, MERRF, MELAS

Test Codes

BAYLOR 2010, Testing requires pathology approval prior to collection.

Department

Send Outs

Instructions

This test is not included in the Beaumont Laboratory testing formulary, however, the Laboratory can facilitate specimen collection.

  • This test requires pathology review. Contact the Send Outs Laboratory at 248-551-9045 before ordering this test.
  • Testing requires the ordering physician to complete forms for the independent clinical laboratory performing the testing.
  • This test will be billed to the patient's insurance. If not covered by insurance, the patient is responsible for the full cost of testing.
  • Specimens received without the appropriate forms and information will not be shipped.
  • Once approved, order test as a Miscellaneous Send Out (XMISC).
  • If approved, due to specimen stability, this test should be collected Monday – Thursday only.

Specimen Collection Criteria

Collect (preferred specimen): Two Lavender-top EDTA tubes, after obtaining necessary pathology approval.

Also acceptable: This assay may also be run on skeletal muscle and tissue, after obtaining necessary pathology approval.

Physician Office/Draw Specimen Preparation

Do not centrifuge. Maintain whole blood at room temperature (20-26°C or 68-78.8°F) prior to transport. Pathology review and all appropriate forms must be completed prior to specimen transport.

Preparation for Courier Transport

Transport: 5.0 mL whole blood with all appropriate forms and information, at room temperature (20-26°C or 68-78.8°F). (Minimum: 3.0 mL)

Rejection Criteria

  • Specimens received without prior Laboratory notification and review.
  • Centrifuged specimens.
  • Frozen specimens.
  • Specimens not collected and processed as indicated. 

In-Lab Processing

Do not centrifuge. Maintain whole blood at room temperature (20-26°C or 68-78.8°F) prior to transport.

Transport: 8.0 mL whole blood with all appropriate forms and information, at room temperature (20-26°C or 68-78.8°F). (Minimum: 3.0 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 7 days
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Baylor Genetics, Houston, TX.

Performed

Varies.
Results available in 3-4 weeks.

Reference Range

By report.

Test Methodology

Next Generation Sequencing.

Interpretation

There are predominant mitochondrial DNA point mutations which cause MELAS (mitochondrial encephalopathy, lactic acidosis and stroke-like episodes), MERRF (myoclonic epilepsy and ragged red fibers), and NARP (neuropathy, ataxia, retinitis pigmentosa) syndromes. In addition to these mutations, there are point mutations causing LHON (Leber's Hereditary Optic Neuropathy), cardiomyopathy, myopathy, peripheral neurodegeneration, neurosensory loss, multisystem disorders, and diabetes/deafness. These mutations can be detected by multiplex PCR amplification of the relevant segments of the mitochondrial genome followed by ASO (allele specific oligonucleotide) probe hybridization.

Clinical Utility

This assay aids in the diagnosis of MELAS (mitochondrial encephalopathy, lactic acidosis and stroke-like episodes).

CPT Codes

81465

Contacts

Last Updated

10/8/2023

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