Different geographic origins of Hb constant spring [alpha(2) codon 142 TAA-> CAA]

Background and Objectives. The occurrence of Hb CS is usually limited to th e geographic area which includes Southern China and South East Asia. In 196 8 Hb CS was also found to occur in the Mediterranean area where it was orig inally described as Hb Athens. We investigated the independent origin of th ese termination codon mutations of the alpha (2)-globin gene by determining the alpha -cluster haplotype and comparing the hematologic data from Hb CS -Hb H patients and their family members. Design and Methods. We studied one Hb CS-Hb H patient of Greek origin and a Sicilian family in which one individual was affected by Hb CS-Hb H, The ha plotype of the Hb CS allele was determined and compared to the haplotype of an Hb CS-Hb H individual of Chinese origin. Results. The haplotype found for the Creek and Sicilian Hb CS was the same but differed significantly from the Asiatic Hb GS mutation. Interpretation and Conclusions. The Hb CS mutation found in both Mediterran ean patients arose independently in the Mediterranean area. The difference in clinical manifestation of the Hb CS-Hb H disease in both patients is les s common but consistent with similar variation in the clinical expression o f analogous Hb Icaria-Hb H disease patients. (C) 2001, Fenata Storti Foundation.