Polymerase chain reaction (PCR)
Agarose gel electrophoresis
Reasons for Rejection
- Frozen specimen
- Clotted specimen
- Wrong collection tube
Please click on the Lab Form Link in the Forms Section to print and complete the Genetic Test Requisition Form. Submission of completed Genetic Test Requisition Form is required, and submission of informed consent form is recommended (but not required).
This is a targeted analysis to detect a common 342-kb deletion in the GJB6 gene (commonly known as the Connexin 30 gene). This test is commonly performed as a reflex test when zero or one mutation is found in the GJB2 gene (commonly known as the Connexin 26 gene; see Test Code: CONN). Presence of a mutation/deletion in both alleles of the GJB6 gene causes autosomal recessive deafness 1B, and presence of a heterozygous GJB2 mutation in conjunction with a heterozygous GJB6 mutation/deletion causes digenic GJB2/GJB6 deafness (autosomal recessive). A missense mutation in the GJB6 gene that has dominant-negative effect causes autosomal dominant deafness 3B; however, this assay will NOT detect missense mutations or other sequence variants (point mutations) in the GJB6 gene, as this is a targeted deletion detection analysis of the GJB6 gene.
When GJB2 sequencing (Connexin 26 Mutation Analysis, Test Code: CONN) and GJB6 deletion detection are ordered simultaneously on the same specimen, then GJB2 sequencing will be performed first, and reflex to GJB6 deletion detection will be performed next if zero or one mutation is found in the GJB2 gene.