Mitochondrial Nonsyndromic Hearing Loss and Deafness Mutation Panel

Clinical Use

Use

The Mitochondrial Nonsyndromic Hearing Loss and Deafness Mutation Panel assesses the presence of pathogenic variants within mitochondrial genes associated with hearing loss. It targets key genes, particularly the commonly implicated MT-RNR1 and MT-TS1. This type of hearing loss is characterized by sensorineural impairments that vary in onset and severity, often exacerbated by environmental factors, particularly aminoglycoside antibiotics. Identifying genetic variants can help determine susceptibility to drug-induced hearing loss and inform clinical management strategies. Genetic inheritance follows a maternal lineage, with implications for family testing and counseling.

Special Instructions

Patients being tested for this condition must provide blood samples collected in an EDTA tube, saliva via the Oragene DNA Self-Collection Kit, or muscle samples stored appropriately. Proper shipping conditions should be maintained to ensure sample integrity; blood and saliva should be shipped at room temperature, while muscle and tissue samples must be frozen and shipped on dry ice. Health professionals should ensure that test code 3031 is used if the variant tested was previously identified in a related family member.

Limitations

The analysis may not reliably detect low levels of mutant heteroplasmy. Variants present at heteroplasmy levels below 50% may remain undetected, which could lead to false negatives. Additionally, this panel is focused on specific mitochondrial genes and may not account for all potential genetic causes of hearing loss. It is also crucial to consider that not all individuals with identified variants will exhibit sensorineural hearing loss due to variable penetrance and influence from environmental factors.

Test Details

New York Approved