Hearing Loss, Nonsyndromic, Connexin 30 (GJB6) 2 Deletions

Background  Information for Hearing Loss, Nonsyndromic, Connexin 30 (GJB6) 2 Deletions:
Characteristics: Moderate to profound nonsyndromic hearing loss (NSHL).
Incidence: Approximately 1 in 30 individuals with NSHL has a GJB6 deletion; 1 in 100,000 in the general population.
Inheritance: Autosomal recessive. Compound heterozygotes for GJB2 and GJB6 mutations are affected. Twenty percent of GJB2 heterozygotes with NSHL have a GJB6 deletion; homozygosity for GJB6 deletions is rare.
Cause: GJB6 gene mutations.
Mutations Tested: 309kb del(GJB6-D13S1830), previously reported as 342kb, and 232kb del(GJB6-D13S1854).
Clinical Sensitivity: Dependent on ethnicity.
Clinical Specificity: 99 percent.
Methodology: Multiplex PCR using deletion-specific primers, followed by capillary gel electrophoresis.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: GJB6 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. Diagnostic errors can occur due to rare sequence variations.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.