Carrier screening or diagnostic testing for Bloom syndrome for individuals of Ashkenazi Jewish descent.
Polymerase Chain Reaction/Fluorescence Monitoring
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
Transport 3 mL whole blood. (Min: 1 mL)
Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes.
Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month
Background information for Bloom Syndrome (BLM), 1 Variant:
Characteristics: Bloom syndrome is characterized by pre- and postnatal growth deficiency, sparse subcutaneous tissue, sun-sensitive telangiectatic hypo- and hyperpigmented skin lesions, chromosome instability causing benign and malignant tumors early in life, and male sterility.
Incidence: 1 in 40,000 in Ashkenazi Jewish individuals.
Inheritance: Autosomal recessive.
Cause: BLM pathogenic variants.
Variant Tested: p.Y736Lfs (c.2207_2212delinsTAGATTC).
Clinical Sensitivity: 97 percent in Ashkenazi Jewish individuals, approximately 3 percent in other ethnicities.
Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring.
Analytical sensitivity and specificity: Greater than 99 percent.
Limitations: Variants other than c.2207_2212delinsTAGATTC will not be detected. 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.
Laboratory Developed Test (LDT)
|Component Test Code*||Component Chart Name||LOINC|
|0051435||Bloom Syndrome (BLM), Allele 1|
|0051436||Bloom Syndrome (BLM), Allele 2|
|0051437||Bloom Syndrome (BLM), Interpretation||46991-6|
|2001300||Bloom Syndrome (BLM), Specimen|
- BLM mutation testing