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Test ID: BLOMP Bloom Syndrome, Mutation Analysis, 2281 delATCTGAinsTAGATTC (2281del6/ins7)

Useful For

Carrier screening for Bloom syndrome in individuals of Ashkenazi Jewish ancestry

 

Confirmation of suspected clinical diagnosis of Bloom syndrome in individuals of Ashkenazi Jewish ancestry

 

Prenatal diagnosis for Bloom syndrome in at-risk pregnancies

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
CULFB Fibroblast Culture for Genetic Test Yes No
CULAF Amniotic Fluid Culture/Genetic Test Yes No
MATCC Maternal Cell Contamination, B Yes No

Testing Algorithm

For prenatal specimens only: If amniotic fluid (nonconfluent cultured cells) is received, amniotic fluid culture/genetic test will be added and charged separately. If chorionic villus specimen (nonconfluent cultured cells) is received, fibroblast culture for genetic test will be added and charged separately. For any prenatal specimen that is received, maternal cell contamination studies will be added.

Method Name

Polymerase Chain Reaction (PCR)

Reporting Name

Bloom Syndrome, Mutation Analysis

Specimen Type

Varies


Advisory Information


 



Additional Testing Requirements


All prenatal specimens must be accompanied by a maternal blood specimen.

-Order MATCC / Maternal Cell Contamination, Molecular Analysis on the maternal specimen.



Shipping Instructions


Specimen preferred to arrive within 96 hours of collection.

Prenatal specimens can be sent Monday through Thursday and must be received by 5 p.m. CST on Friday in order to be processed appropriately.



Specimen Required


Submit only 1 of the following specimens:

 

Specimen Type: Whole blood

Container/Tube:

Preferred: Lavender top (EDTA) or yellow top (ACD)

Acceptable: Any anticoagulant

Specimen Volume: 2.6 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

Specimen Stability Information: Ambient (preferred)/Refrigerated/Frozen

 

Prenatal Specimens

Due to the complexity of prenatal testing, consultation with the laboratory is required for all prenatal testing.

 

Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20 mL

Specimen Stability Information: Refrigerated (preferred)/Ambient

 

Specimen Type: Chorionic villi

Container/Tube: 15-mL tube containing 15 mL of transport media

Specimen Volume: 20 mg

Specimen Stability Information: Refrigerated

 

Acceptable:

Specimen Type: Confluent cultured cells

Container/Tube: T-25 flask

Specimen Volume: 2 Flasks

Collection Instructions: Submit confluent cultured cells from another laboratory.

Specimen Stability Information: Ambient (preferred)/Refrigerated


Specimen Minimum Volume

Blood: 0.5 mL; Amniotic Fluid: 10 mL; Chorionic Villi: 5 mg

Specimen Stability Information

Specimen Type Temperature Time
Varies Varies

Clinical Information

Bloom syndrome is characterized by short stature, sun sensitivity, susceptibility to infections, and a predisposition to cancer. Mutations in the BLM gene lead to genetic instability (increased chromosomal breakage and sister chromatid exchange) and cause the clinical manifestations of the syndrome. The protein encoded by the BLM gene is a helicase involved in maintaining DNA integrity. The carrier rate in the Ashkenazi Jewish population is 1 in 107. There is a common mutation in the Ashkenazi Jewish population: 2281delATCTGAins TAGATTC (2281del6/ins7). The carrier detection rate for this mutation is above 99%.

Reference Values

An interpretive report will be provided.

Interpretation

An interpretive report will be provided.

Clinical Reference

1. Gross SJ, Pletcher BA, Monaghan KG: Carrier screening in individuals of Ashkenazi Jewish descent. Genet Med 2008 Jan;10(1):54-6

2. Hickson ID: RecQ helicases: Caretakers of the genome. Nat Rev Cancer 2003;3(3):169-178

Day(s) and Time(s) Performed

Tuesday; 10 a.m.

Analytic Time

9 days

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

81209-BLM (Bloom syndrome, RecQ helicase-like) (eg, Bloom syndrome) gene analysis, 2281 del6ins7 variant

Fibroblast Culture for Genetic Test

88233-Tissue culture, skin or solid tissue biopsy (if appropriate)

88240-Cryopreservation (if appropriate)

 

Amniotic Fluid Culture/Genetic Test

88235-Tissue culture for amniotic fluid (if appropriate)

88240-Cryopreservation (if appropriate)

 

Maternal Cell Contamination, B

81265-Comparative analysis using Short Tandem Repeat (STR) markers; patient and comparative specimen (eg, pre-transplant recipient and donor germline testing, post-transplant non-hematopoietic recipient germline [eg, buccal swab or other germline tissue sample] and donor testing, twin zygosity testing or maternal cell contamination of fetal cells (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BLOMP Bloom Syndrome, Mutation Analysis In Process

 

Result ID Test Result Name Result LOINC Value
53136 Result Summary 50397-9
53137 Result 32640-5
53138 Interpretation In Process
52426 Additional Information 48767-8
53139 Reason for Referral 42349-1
53140 Specimen 31208-2
53141 Source 31208-2
53142 Released By No LOINC Needed

Forms

1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.

2. Molecular Genetics: Biochemical Disorders Patient Information (T527) in Special Instructions