Beta Hemoglobin DNA Sequencing
General Information
- Lab Name
- Beta Hemoglobin DNA Sequence
- Lab Code
- HBSEQ
- Epic Ordering
- Beta Hemoglobin DNA Sequence
- Description
There are currently over 800 hemoglobin variants catalogued, of which approximately 500 are due to mutations in the beta-globin gene. In addition, approximately 95% of beta-thalassemia is caused by point mutations. This test, which sequences the coding regions and introns of the beta-globin gene (HBB) in both directions, identifies hemoglobin variants that are not easily diagnosed by electrophoresis/HPLC and can determine the cause of beta-thalassemia.
Indications for testing include:
- Identification of hemoglobin variants detected by electrophoresis or HPLC
- Differential diagnosis of microcytic anemia
- Molecular characterization of beta-thalassemia mutations
- Testing of a relative of an individual with a known beta-globin mutation
- Prenatal diagnosis of potentially severe beta-thalassemia
- Characterization of the sickle-cell mutation
Notes: To order testing for a relative of an individual with a known beta-globin mutation, see the Laboratory Medicine Online Test Guide for Beta Hemoglobin Sequencing, Relative [HBREL]
- References
- Origa R. Beta-Thalassemia. GeneReviews: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. 2000 Sep 28 [updated 2018 Jan 25]. 20301599
- Old JM. Screening and genetic diagnosis of haemoglobin disorders. Blood Rev 2003, 17:43-53. 12490210
- Globin Gene Server: http://globin.cse.psu.edu/
- Forms & Requisitions
- Synonyms
- Globin, HBB, Hemoglobin C, Hemoglobinopathy, Hemoglobin S, Sickle Cell, Thalassemia intermedia, Thalassemia major
- Components
-
Code Name HBSRES Hb beta Results HBSCI Hb beta Clin Info HBSINT Hb beta Interpretation HBSMTH Hb beta Methods and Info
Interpretation
- Method
DNA sequencing of the coding regions, introns, and flanking sequences of the hemoglobin beta (HBB) gene in both directions to detect point mutations causing beta globin variants and beta thalassemia.
This test sequences bidirectionally a 2 kb contiguous region of the HBB (beta globin) gene from approximately bases 61941 to 63927 of Genbank U01317, corresponding to bases minus 195 to plus 1792 relative to the start of transcription. Patient sequences are compared against Genbank U01317 as genomic reference sequence to detect mutations. Mutations are reported at the genomic level, with base 1 corresponding to the start of transcription. Mutations that change an amino acid are reported at the protein level according to the sequence of the mature protein without its initiator methionine, and may also be described by the traditional name of the hemoglobin variant.
Correspondence between this mutation nomenclature system and the HGVS nomenclature system may be found at the web site http://globin.cse.psu.edu.
This test was developed and its performance characteristics determined by the Department of Laboratory Medicine at the University of Washington.
- Reference Range
- See individual components
- Ref. Range Notes
No mutation detected.
- References
- Origa R. Beta-Thalassemia. GeneReviews: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. 2000 Sep 28 [updated 2018 Jan 25]. 20301599
- Old JM. Screening and genetic diagnosis of haemoglobin disorders. Blood Rev 2003, 17:43-53. 12490210
- Globin Gene Server: http://globin.cse.psu.edu/
- Guidelines
Ordering & Collection
- Specimen Type
- Blood, amniocytes, chorionic villus tissue or cultured cells.
- Collection
-
BLOOD:
- Adult: 5 mL LAVENDER TOP tube
- Child: 2 mL LAVENDER TOP tube
- Also acceptable: YELLOW TOP (ACD) tube
- Unacceptable: Heparin green top tubes
AMNIOCYTES or CULTURED CHORIONIC VILLUS CELLS:
- Two (2) T23 or One (1) T75 flask (minimum 1-T25 flask)
CHORIONIC VILLIS and/or TISSUE:
- In sterile tube or culture media, at least 5 mg tissue.
Prenatal testing requires concomitant testing for maternal cell contamination (see Online Test Guide, Lab Mnemonic Maternal Cell Contamination [MCC] for ordering and specimen requirements)
- Forms & Requisitions
- Handling Instructions
Blood: Refrigerate whole blood up to 1 week.
Amniocytes & cultured CVS cells: hold flasks at room temperature.
Chorionic villi &/or tissue: hold at room temperature.
Outside Laboratories: Ship whole blood at ambient temperature for receipt within 1 week of specimen collection.- For cultured amniocytes or chorionic villus cells and for CVS or other tissue, transport and store at room temperature within 24 hours of obtaining CV or removing cultured cells from incubator.
- Quantity
-
requested: Entire specimen
minimum: Blood: 1 mL. Amniocytes, cultured chorionic villus cells, chorionic villi or tissue: as above.
Processing
- Processing
Please notify genetics about amniocytes, cultured chorionic villus cells, chorionic villi or tissue.
- Transport Temperature
Performance
- LIS Dept Code
- Genetics (GEN)
- Performing Location(s)
-
UW-MT Genetics Attention: Genetics Lab
Clinical lab, Room NW220
University of Washington Medical Center
1959 NE Pacific Street
Seattle, WA 98195Tel: 206-598–6429 M–F (7:30 AM–4:00 PM)
Fax: 206-598–0304
Lab email: genelab@uw.eduTel (EXOME only): 206-543-0459
Manager
Joe Bernal, jbernal@uw.edu
Genetic Counselors
Angela Jacobson, MS, LGC agibson@uw.edu
Sandra Coe, MS,LGC, scoe20@uw.edu
Dru Leistritz, MS, LGC, dru2@uw.edu (EXOME testing only)
Daniel W. Serber, PhD, MS, LCGC, dwserber@uw.eduVariant Review Scientist
Ankita Jhuraney, PhD
Sarah Paolucci, MA, MS, LGC, spaolucc@uw.edu
Catherine A. Darcey, MScFaculty
Colin C. Pritchard, MD, PhD
Brian H. Shirts, MD, PhD
Christina Lockwood, PhD, DABCC
Stephen Salipante, MD, PhD
Eric Konnick, MD, MS
Niklas Krumm, MD,PhD
Vera Paulson, MD, PhD
Jillian Buchan, PhD, FACMG - Frequency
- Performed weekly. Results within 3 weeks.
- Available STAT?
- No
Billing & Coding
- CPT codes
- 81364
- Billing Comments
For pricing information, contact Client Support Services 206-520-4600 or 800-713-5198.
- LOINC
- 21689-5