• 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 BLM gene is associated with autosomal recessive Bloom syndrome (MedGen UID: 2685). Additionally, the BLM gene has preliminary evidence supporting a correlation with autosomal dominant colorectal cancer in individuals who carry a single pathogenic variant (PMID: 12242432, 26358404, 12702560, 18210922).

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Invitae tests that include this gene:

The gene BLM encodes a RecQ helicase protein. Helicases unwind DNA so that it can be it can be replicated in preparation for cell division. The BLM protein helps maintain the stability and structure of the DNA during this process. Loss of BLM function results in chromosomal breaks and rearrangements; creating pathogenic variants that contribute to cancer progression, immunodeficiency, and other symptoms.

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
BLM NM_000057.3