What is Hb Bart's?

Answer 1

Hb Barts is associated with one of the alpha-Thalassemias, namely homozygous alpha^0. The absence of all four alpha globin genes results in the alpha globin chain not being produced. The only types of haemoglobin that can be produced are Gower 1 (zeta2eta2) and Portland (zeta2gamma2) which are both embryonic haemoglobins. At around 6wks the alpha globin production is ~50% of the total. In the absence of globin chains the fetal haemoglobin (alpha2gamma2) cannot be produced so the gamma globulin chain precipitate out in the red blood cells as tetramers (gamma4). These tetramers are referred to as Hb Bart.

Answer 2

Hb Bart's is a severe form of alpha thalassemia that results in a high level of fetal hemoglobin (Hb) in the blood. It is caused by mutations that prevent the production of adult hemoglobin, leading to severe anemia and other complications. Hb Bart's is usually fatal before or shortly after birth.