Hb F-Bonaire-Ga or alpha 2 A gamma 2 39(C5) Gln replaced by Arg, characterized by high pressure liquid chromatographic and microsequencing procedures.

A slowly moving gamma chain variant was discovered in the cord blood of a baby of English-Vietnamese descent. The abnormality concerned the substitution of Gln residue in position 39(C5) of the A gamma chain by an Arg residue resulting in an -Arg-Arg- sequence at positions 39 and 40. The quantity of the A gamma chain variant was nearly 10% of the total Hb F with 15% of the Hb F having normal A gamma chains and 75% of Hb F having G gamma chains. High pressure liquid chromatographic and microsequencing methods greatly facilitated the structural analyses.