Associated disorders

The NBN gene is associated with an increased risk for autosomal dominant breast cancer in individuals who carry a single pathogenic NBN variant (PMID: 21514219, 16770759). Additionally, the NBN gene is associated with autosomal recessive Nijmegen breakage (NBS) syndrome (MedGen UID: 140771).

NBN is a tumor-suppressor gene that encodes nibrin, a protein that functions in cellular response to DNA damage and the maintenance of chromosomal integrity as part of the MRE11/RAD50/NBN double-strand break repair complex. Nibrin also has a role in regulating cell division and proliferation. Loss of nibrin function due to pathogenic variants causes defective DNA repair, leading to accumulation of DNA damage, thereby increasing the risk of tumor formation. A lack of functional nibrin also results in decreased immune cell proliferation.

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, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.

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
NBN NM_002485.4