Ordering Recommendation

Carrier screening or diagnostic testing for Bloom syndrome for individuals of Ashkenazi Jewish descent.

Mnemonic
BLM
Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Tue, Fri

Reported

5-10 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month

Reference Interval

By report

Interpretive Data

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.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81209

Components
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
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • BLM mutation testing
Bloom Syndrome (BLM), 1 Variant