ARUP's Laboratory Test Directory
| 0050528: Hemoglobin Bart |
| Test Mnemonic: BARTS | |
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Methodology: High Performance Liquid Chromatography
Performed: Mon Reported: 1-8 days |
| Specimen Required: | |
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Collect: 2 mL cord blood (EDTA) or one 1 mL lavender (EDTA) from an infant less than 3 months of age. Also acceptable: pink (K2EDTA).
Transport: 1 mL whole blood at 2-8°C. Unacceptable Conditions: Ambient or frozen samples, adult samples, or samples collected from infants older than 3 months of age. Stability: Ambient: Unacceptable; Refrigerated: 3 days; Frozen: Unacceptable |
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| Reference Interval: |
| Less than 1.0% |
| Interpretive Data: | |||||||||||||
a-Thalassemia is caused by underproduction of the a-globin chains that make up hemoglobin molecules. Hb A (a2 b2) and Hb A2 (a2 D2) contain a-chains and therefore are insufficiently produced in a-thalassemia. In this condition, g-globin genes become active early in life, producing homotetramers of g (g4 or Hb Bart). After the first few months of life, when b-chain production is established, homotetramers of b (b4 or Hb H) become predominant. Demonstration of either Hb Bart or Hb H in the blood is proof of reduced a-chain production, and hence a-thalassemia. Accurate genotyping of patients with different amounts of Hb Bart will depend on family studies, hematological parameters, and DNA analysis.
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| CPT Code(s): | |
| 83021 |