ARUP's Laboratory Test Directory

0050388: Beta Globin (HBB) Full Gene Sequencing, Fetal

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Time Sensitive
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Patient History for Fetal Molecular Testing

Test Mnemonic: BGSEQ FE
Methodology: Polymerase Chain Reaction/Sequencing

Performed: Varies

Reported: 5-7 days

Specimen Required:  
Collect: and Transport: Cultured cells: Two T-25 flasks at 80% confluent of cultured amniocytes. Fill flasks with culture media to ship at 20-25°C.  Backup cultures must be retained at the client's institution until testing is complete. If the client is unable to culture amniocytes, this can be arranged by contacting ARUP Client Services at (800) 522-2787.
Maternal sample: One 5 mL whole blood lavender (EDTA) or yellow (ACD Solution A or B) at 20-25°C.

Remarks: Fetal samples are CRITICAL AMBIENT and must be received within 48 hours of shipment due to lability of cells.
Maternal sample is recommended for proper test interpretation, order maternal Cell Sample (0050608). 

Stability: Fetal: Ambient: 2 days; Refrigerated: Unacceptable; Frozen: Unacceptable
Maternal: Ambient: 24 hours; Refrigerated: 5 days; Frozen: Unacceptable

Reference Interval:
Normal: The sample has a normal sequence of the b-globin gene.  No mutations were identified within the b-globin coding region, the intron/exon splice site boundaries or intronic positions the IVS-II-654, IVS-II 705, or IVS-II 745.  Gene deletions or mutations causing thalassemias or hemoglobinopathies outside of these regions will not be identified.

Interpretive Data:
Background Information:
Characteristics: Mutations can result in or thalassemias (insufficient or absent beta chain production, respectively) as well as structural hemoglobinopathies.
Incidence: Varies with ethnicity.
Inheritance: Usually autosomal recessive, infrequently autosomal dominant.
Cause: Mutations in the HBB gene.
Mutations tested: The complete protein coding sequence with exon/intron boundaries, proximal promoter, 5' and 3' untranslated regions, and intronic mutations IVS-II-654, IVS-II-705 and IVS-II-745 and the 619del common in the Asian Indian population.
Clinical Sensitivity: Up to 97%, depending upon ethnicity.
Methodology: PCR amplification followed by bidirectional sequencing. For 619del, PCR followed by gel electrophoresis.
Analytical sensitivity: 99%
Limitations: Specificity may be compromised by rare primer site mutations. Large-scale deletions or mutations in distal regulatory elements, such as the locus control region, will not be detected.

For quality assurance purposes, ARUP Laboratories will provide a confirmation of the above result at no charge.  Following delivery, please collect a cord blood sample from the infant in a lavender (EDTA) or yellow (ACD Solution A) tube.  Please specify on the test request form that this is a confirmatory study to be performed at no charge. Please provide the mother's name for specimen identification purposes.

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.

Please refer to Statement C in the Compliance Statements section in the front of the Laboratory Test Directory.



CPT Code(s):
B-Globin: 83890 Isolation; 83898 x3 Amplification; 83894 Gel separation;  83904 x3 Sequencing; 83909 Capillary electrophoresis; 83912 Interpretation and report.  FCC: 83900 Multiplex amplification; 83901 x14 Additional Amplification; 83909 Separation capillary electrophoresis.  For MCC Maternal cell (0050608) add: 83890 Isolation; 83900 Multiplex amplification; 83901 x14 Additional amplification; 83909 Capillary electrophoresis; 83912 Interpretation and report