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Hearing Loss, Nonsyndromic, Mitochondrial DNA 2 Mutations
2002044
Ordering Recommendation

For individuals with nonsyndromic hearing loss and no identified mutations in GJB2 or GJB6.

Mnemonic
HL MTDNA
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Varies
Reported
7-14 days
New York DOH Approval Status
This test is New York DOH approved.
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
 
Collect
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 2 mL) 
Storage/Transport Temperature
Refrigerated. 
Unacceptable Conditions
 
Remarks
 
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
By report
Interpretive Data
Background Information for Hearing Loss, Nonsyndromic, Mitochondrial DNA 2 Mutations
Characteristics: mt-RNR1 m. 1555A>G is associated with non-syndromic hearing loss (NSHL) and a predisposition to aminoglycoside ototoxicity resulting in stable, severe to profound hearing loss with variable age of onset. mt-TS1 m.7445A>G is associated with progressive, mild to severe hearing loss of childhood onset and palmoplantar keratoderma.
Incidence: Approximately 1 in 50 individuals with NSHL has a mitochondrial mutation; 1 in 140,000 in the general population.
Inheritance: Dominant maternal inheritance.
Cause: Mitochondrial DNA mutations.
Mutations Tested: m.1555A>G and m.7445A>G.
Clinical Sensitivity: Dependent on ethnicity.
Methodology: Targeted bidirectional sequencing of mitochondrial mt-RNR1 m.1555A>G and mt-TS1 m.7445A>G.
Analytical Sensitivity and Specificity: 99 percent
Limitations:Diagnostic errors can occur due to rare sequence variations. Mutations other than the two targeted will not be identified. The etiology of hearing loss due to other genetic or environmental causes will not be determined.

Compliance Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
CPT Code(s)
81401
Components
Component Test Code*Component Chart NameLOINC
2002045HL mtDNA Specimen31208-2
2002046Hearing Loss, Nonsyndromic mtDNA Interp40995-3
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • CX26 SEQ
  • HL PANEL
  • mtDNA sequending assay