ARUP's Laboratory Test Directory

Beta Globin (HBB) Sequencing, Fetal : 0050388
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Time Sensitive
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Patient History and Technical Information


Mnemonic: BGSEQ FE

Ordering Recommendation: Confirmatory genetic test on fetal samples for the prenatal detection of structural hemoglobinopathies and beta thalassemia.
Methodology: Polymerase Chain Reaction/Sequencing
Performed: Varies
Reported: 5-10 days
Specimen Required: 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.


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 (collection to initiation of testing): Fetal Specimen: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Whole Blood or Maternal Cell contamination Specimen:
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable


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 HBB coding 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:
Rare diagnostic errors can occur due to primer site mutations. 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.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
CPT Code(s): 81404; Fetal Cell Contamintaion (FCC): 81265;