Aminoglycoside-Induced Hearing Loss, Targeted Variant Testing, Droplet Digital PCR, Varies

Casandra

Casandra Test Code MC76873Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID AIHL

Aminoglycoside-Induced Hearing Loss, Targeted Variant Testing, Droplet Digital PCR, Varies

Clinical Use

Use

Identification of individuals who may be at risk for aminoglycoside-induced hearing loss (AIHL). Establishing a diagnosis of late-onset sensorineural hearing loss associated with aminoglycoside exposure. Identifying mitochondrial variants associated with AIHL, allowing for predictive testing of at‑risk family members. The test detects two mitochondrial RNR1 (MT‑RNR1) variants, m.1555A>G and m.1494C>T, the most common variants associated with aminoglycoside‑induced ototoxicity. It employs droplet digital PCR (ddPCR) for detection.

Special Instructions

For cultured fibroblast specimens, a fibroblast culture will be performed at an additional charge; if viable cells are not obtained, the client will be notified. For cord blood specimens with an accompanying maternal specimen, maternal cell contamination studies will be performed at additional charge. New York clients require informed consent documented on the request form or electronically. Consent forms and patient information materials (including Spanish versions) are available.

Limitations

Saliva and blood spot specimens are acceptable but not recommended due to lower DNA yield and potential impact on test performance; specific gene regions unable to be interrogated will be noted. Extracted DNA must be from a CLIA‑certified laboratory; extraction method compatibility is not assured for all platforms; repeat will be attempted if testing fails, failure will be reported and charged. Hematopoietic stem cell transplant history interferes with testing. DNA quality issues may result in failed or incomplete testing.

Test Details

New York Approved