Rare hemoglobin variant Hb Yaizu observed in Turkey

Objective: To determine the characteristic features of the rare hemoglobin (Hb) variant Hb Yaizu to enable laboratory diagnosis of the hemoglobin variants during screening programs. Materials and Methods: Genomic DNA was obtained from the 4 members of a family living in Denizli province, an Aegean region of Turkey. Blood cell counts, hemoglobin composition, hemoglobin electrophoresis (both alkaline and acid), HPLC analysis, DNA sequencing and beta globin gene cluster haplotypes were done. Results: Hb Yaizu carriers were apparently healthy individuals. Hb Yaizu was slightly faster than Hb S at alkaline pH, but slower than Hb S at acidic pH in hemoglobin electrophoresis. An abnormal hemoglobin peak was observed with a retention time of 4.77 min in HPLC analysis attributed to Hb Yaizu. Two members of the family were heterozygous Hb Yaizu [beta 79(EF3) Asp>Asn] confirmed by DNA sequencing. The mutation was found to be linked with the Mediterranean haplotype I [+ - - ++]. Conclusion: We have presented the details of Hb Yaizu, a rare hemoglobin variant that may be important to hemoglobinopathy screening programs, although its clinical significance is unclear. Copyright © 2008 S. Karger AG

Türkiye’de gözlenen ilk Hb Tunis [beta124(H2)Pro>Ser] olgusu

Hb Tunis [beta124(H2)Pro>Ser] was reported from Tunisia in 1988. This hemoglobin variant was detected by isoelectric focusing moving just ahead of Hb A. It cannot be identified by standard hemoglobin electrophoresis due to its similar mobility to Hb A. It has normal stability and oxygen affinity and does not produce any clinical symptoms. Here, we report a heterozygous Hb Tunis [beta124(H2)Pro>Ser] case discovered for the first time in Turkey in a premarital screening program. This hemoglobin variant can be identified with high performance liquid chromatography analysis confirmed with DNA sequencing. We emphasize in our study the importance of an interdisciplinary collaborative study at the provincial basis for the success of the hemoglobinopathy control program