Newborn Screening for Metabolic and Sickle Cell Disorders Program
Alpha Thalassemia and Bart's Hemoglobin
Brief Description
These groups of autosomal recessive disorders result from the decreased or absent production of alpha (a) globin chains in structurally normal hemoglobin. There are normally four genes for alpha globin production so that the loss of one to four genes is possible.
Prevalence
About 2% of infants will have Hemoglobin Bart's in Georgia.
Analyte/Lab Method
Hemoglobin fractions by isoelectric focusing (IEF), HPLC, and Citrate Agar electrophoresis
Abnormal Result
FA + Bart's
Timing Effect
Hemoglobin Bart's disappears rapidly after birth in most infants.
Causes of False Positives/Negatives
Transfusions, post-mature infants, late collection.
Treatment
None needed
Symptoms
The lack of all four alpha genes causes hydrops fetalis, which is usually fatal in utero. The absence of three genes causes Hemoglobin H disease, which is a mild to moderately severe form of thalassemia. The absence of two genes, known as alpha thalassemia minor, causes a mild anemia, which resembles iron deficiency anemia and microcytosis. There are no clinically detectable problems associated with the loss of only one gene.
Comments
Only infants with severe anemia need clinical follow-up.
Follow-up Program/Treatment Center
Newborn Screening Unit
Georgia Department of Public Health
NBS Program Coordinator: (404) 463-0815
Grady Health System
On-Call MD: (404) 616-3572
Additional Resources
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