16. In newborn screening program detection of Hb Barts in a range of 20-25% is suggestive of ?
[1] HbH disease
[2] Alpha thal silent carrier
[3] Alph thal trait
[4] Hb Barts hydrops fetalis
Answer = [1] HbH disease
HPLC at birth in alpha thal syndromes.
*Hb Bart’s hydrops fetalis syndrome: Hb Bart’s > 80%, a variable amount of Hb Portland and HbH present, No HbA
*HbH disease: HbH > 20% at birth
*α-thalassemia trait: Hb Bart’s in newborns 4-10% may be up to 20 %
*α-thalassemia silent carrier: Hb Bart’s in newborns is up to 2%