Days Set Up
Monday - Friday
Analytic Time

14 - 21 days

MiChart Code
Connexin 26 (GJB2) Gene Sequencing
Soft Order Code

Test Updated:


Generic Peds Genetics Test
GJB2 Mutation Detection
GJB2 Sequencing
Connexin 26 Sequencing
Connexin 26 Inv+Seq Shadow
Hearing Loss Panel
Connexin 30 (GJB6) Deletion Analysis
GJB6 346kb Deletion
GJB2 35delG Mutation
Connexin 30 deletion Shadow
Connexin 30 (GJB6) Deletion Analysis

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All specimens should be accompanied by a requisition.

Submitting Specimens

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Order Kits and Supplies

MLabs provides all the supplies necessary for the collection of specimens.

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Test Overview

Test Methodology

GJB2 (exonic and intronic splice site consensus) sequences are amplified using specific primers, and bidirectionally sequenced using a fluorescent method. The 2 most frequent large deletions in GJB6 are detected by a PCR-based method.

Test Usage

Confirmation of a diagnosis of hearing loss with a genetic etiology or carrier testing in families with a known GJB2 mutation. Connexin tesing will be performed as a sequential reflexive assay consisting of Connexin 26 (GJB2) Mutation Analysis and Connexin 30 (GJB6) Deletion Analysis. A patient with non-syndromic hearing loss can have two mutations in Connexin 26, two mutations in Connexin 30, or one mutation in Connexin 26 and one mutation in Connexin 30. Mutations in the GJB2 (Connexin 26) gene account for 30-70% of non-syndromic recessive (and a small number of autosomal dominant) deafness in Caucasian populations. Approximately 40% of individuals with sporadic non-syndromic hearing loss also carry GJB2 mutations.

Reference Range

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Offsite

Collect specimen in a lavender top tube. Send intact specimen within 24 hours if stored at room temperature or within 5 days if stored refrigerated. Include the patient's family history, pedigree, and ethnicity on the test requisition. Obtaining informed consent from the patient prior to genetic testing is strongly recommended. If desired, a UMHS Request and Consent for Genetic Testing form can be obtained from the MMGL Molecular Genetics Laboratory by contacting the MLabs Client Services Center at 800-862-7284 or online at….

Lavender Top Tube
Normal Volume
5 - 10 mL EDTA whole blood
Minimum Volume
2 mL EDTA whole blood

Billing Information

CPT Code
CX26SS: 81252; CX30DS: 81254
Pro Fee Code

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.