Diagnostic testing for Bloom syndrome. Carrier screening for Bloom syndrome.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Pre-and postnatal growth deficiency, sparse subcutaneous tissue, sun-sensitive telangiectatic hypo-and hyperpigmented skin lesions, and chromosome instability causing benign and malignant tumors early in life.
Incidence: 1 in 40,000 in Ashkenazi Jewish individuals, unknown in other ethnicities.
Inheritance: Autosomal recessive.
Cause: PathogenicBLM gene mutations.
Mutation Tested: p.Y736Lfs (c.2207_2212delinsTAGATTC).
Clinical Sensitivity: 95 percent in Ashkenazi Jewish individuals.
Methodology: Multiplex polymerase chain reaction and Detection Primer Extension.
Analytical sensitivity and specificity: Greater than 99 percent.
Limitations: Mutations other than those tested will not be detected. Diagnostic errors can occur due to rare sequence variations.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|0051435||Bloom Syn (BLM) 1 Mutation, Allele 1|
|0051436||Bloom Syn (BLM) 1 Mutation, Allele 2|
|0051437||Bloom Syn (BLM) 1 Mutation, Interp||46991-6|
|2001300||Bloom Syn (BLM) 1 Mutation, Specimen|
- BLM mutation testing