• Turnaround time:
    10–21 calendar days (14 days on average)
  • Preferred specimen:
    3mL whole blood in a purple-top tube
  • Alternate specimens:
    DNA or saliva/assisted saliva
  • Sample requirements
  • Request a sample kit




Associated disorders

The GJB1 gene (also known as Connexin 32 or Cx32) is associated with X-linked Charcot-Marie-Tooth disease type 1X (CMT1X) (MedGen UID: 98290).

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Invitae tests that include this gene:

An estimated 90% of X-linked CMT and 10%-20% of all CMT cases are caused by pathogenic variants in GJB1.

The gene GJB1 encodes the gap junction protein connexin 32, which is expressed in the liver, pancreas, and kidney and in the nervous system. In both the peripheral and central nervous system, this protein forms channels through the myelin sheath, an insulating structure essential for proper function of neurons.

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence in the transcript listed below. In addition, analysis covers the select non-coding variants specifically defined in the table below. Any variants that fall outside these regions are not analyzed. Any specific limitations in the analysis of these genes are also listed in the table below.

Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
GJB1 NM_000166.5