Molecular Test Listing

Molecular Requisition

MELAS:

Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) results from a mutation in the mitochondrial DNA of the cell. Children with MELAS typically present with stunted growth, episodic vomiting, seizures, and recurrent cerebral insults resembling strokes and causing hemiparesia, hemianopia, or cortical blindness.

The disease is inherited maternally. Due to the dosage effects as a result of heteroplasmy (varying mixture of mutant and normal mitochondrial DNA), all these conditions can appear in families with no apparent past history and appear unevenly between siblings. The principle mutation is A3243G in the mitochondrial leucine tRNA.

REASONS FOR REFERRAL:
  • Individuals with unexplained weakness, seizures, dementia, episodic vomiting, cortical blindness, hemianopia, and/or lactic acidosis.
  • To disriminate between MELAS and other mitochondrial diseases in an affected individual.
  • To accurately predict the risk of having a child with the condition.

  • This testing may be combined with testing for MERRF and NARP in a Mitochondrial Panel.

TESTING METHODOLOGY:

  • PCR amplification of the region including the A3243G mutation in the mitochondrial DNA, followed by mutation specific restriction enzyme digestion.

SPECIMEN REQUIREMENTS:
  • Blood EDTA (purple top) tubes:  

            Newborn: minimum 1-2 mL          

            Child/Adult: prefer 2 tubes of 3-5 mL

  • Prenatal testing: Please contact the laboratory for instructions.

  • A Molecular Genetics Laboratory Test Requisition must accompany the specimen. Contact the Molecular Laboratory at 918-502-1721 to obtain further information.

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    TURNAROUND TIME:     8 working days

    CPT CODES: