Hb F-Catalonia or alpha 2G gamma(2)15(A12)Trp----Arg

Hb F-Catalonia, a G gamma chain variant with a Trp----Arg substitution at position gamma 15(A12), was observed in two Spanish newborn babies from Northeastern Spain. Analyses were performed with different reversed phase high performance liquid chromatographic procedures that allowed the identification of the amino acid replacement in only a minute quantity of the isolated G gamma X chain.