Beta Globin (HBB) Sequencing, Fetal
0050388
Ordering Recommendation
Confirmatory genetic test on fetal samples for the prenatal detection of structural hemoglobinopathies and beta thalassemia.
Mnemonic
BGSEQ FE
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Varies
Reported
5-10 days  
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
  
Collect
Fetal Specimen: Two T-25 flasks at 80% confluent of cultured amniocytes. If the client is unable to culture amniocytes, this can be arranged by contacting ARUP Client Services at (800) 522-2787. Or amniotic fluid.
AND Maternal Cell Contamination Specimen:
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

OR Whole Blood
in lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).  
Specimen Preparation
Cultured Amniocytes: Fill flasks with culture media. Transport two T-25 flasks at 80% confluent of cultured amniocytes filled with culture media. Backup cultures must be retained at the client's institution until testing is complete.
OR Amniotic Fluid:
Transport 10 mL unspun fluid. (Min: 5 mL)
AND Maternal Cell Contamination Specimen:
Transport 3 mL whole blood (Min: 1 mL)

OR Whole Blood:
Transport 3 mL whole blood (Min: 1 mL)  
Storage/Transport Temperature
Cultured Amniocytes: CRITICAL ROOM TEMPERATURE. Must be received within 48 hours of shipment due to liability of cells.
Amniotic fluid:
Room temperature.
Whole Blood or Maternal Cell Contamination Specimen:
Room temperature.  
Unacceptable Conditions
  
Remarks
Maternal specimen is recommended for proper test interpretation. Order Maternal Cell Contamination. Patient History Form is available on the ARUP Web site or by contacting ARUP Client Services.  
Stability
Fetal Specimen: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Whole Blood or Maternal Cell contamination Specimen:
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
   
Interpretive Data
Background Information Beta Globin (HBB) Sequencing, Fetal:
Characteristics: S
tructural hemoglobinopathies or thalassemias (insufficient or absent beta-chain production).
Incidence:
Varies with ethnicity.
Inheritance:
Usually autosomal recessive, infrequently autosomal dominant.
Cause
: Pathogenic mutations in the HBB gene.
Clinical Sensitivity:
Up to 97 percent, depending upon ethnicity.
Methodology:
Bidirectional sequencing of the HBBcoding regions, intron-exon boundaries, proximal promoter, 5' and 3' untranslated regions, and intronic mutations IVS-II-654, IVS-II-705 and IVS-II-745. The 619del mutation is detected by PCR followed by gel electrophoresis.
Analytical sensitivity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Large deletions, other than 619del, and mutations in distal regulatory elements are not detected.

For quality assurance purposes, ARUP Laboratories will confirm the above result at no charge following delivery. Order Confirmation of Fetal Testing and include a copy of the original fetal report (or the mother's name and date of birth) with the test submission. Please contact an ARUP genetic counselor at (800) 242-2787 extension 2141 prior to specimen submission.

This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.





See Compliance Statement C: www.aruplab.com/CS
Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test; however, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
 
Note
 
CPT Code(s)
81404; Fetal Cell Contamintaion (FCC): 81265;
Components
Component Test Code*Component Chart Name
0050548Maternal Cell Contamination, Fetal Spec
0050578Beta Globin Full Gene Sequencing
0050612Maternal Cell Contam, Maternal Spec
0051366BGSEQ FE 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
  • Carrier testing Beta thalassemia
  • Fetal HBB mutation testing