Hb A2-Monreale [delta146(HC3)His-->Arg], a novel delta chain variant detected in west Sicily.

We report a novel mutation, Hb A2-Monreale [delta146(HC3)His-->Arg], detected by cation exchange high performance liquid chromatography in a family from West Sicily. The mutation is due to a CAT-->CGT substitution at codon 146 of the delta-globin gene. The two carriers had reduced levels of normal Hb A2 (1.1%), but comparable levels (0.9%) of the Hb A2 variant. Most likely the new variant has the same characteristics as Hb Cochin-Port Royal [beta146(HC3)His-->Arg], that is stable but has a 75% reduction of the Bohr effect. The finding of the new variant increases the genotype heterogeneity of the delta-globin gene in the Mediterranean area, and is relevant to the study and prevention of Cooley's Anemia.