Phenotype and genotype frequency of ß-thalassemia and sickle cell disease carriers in Halkidiki, Northern Greece.

A decade of screening (years 2000 to 2010) for hemoglobinopathies in 3,931 patients was performed at the General Hospital of Poligiros, Halkidiki, Northern Greece. Among the patients examined, 10.8% heterozygotes for ß-thalassemia (ß-thal) were found, as well as 4.1% with sickle cell disease and 1.2% with double ß-thal/Hb S [ß6(A3)Glu→Val] heterozygosity. Iron deficiency was observed in 23.4%. The geographical distribution in the region revealed a substantial incidence of hemoglobinopathies even in mountainous areas. This pattern did not follow the typical distribution according to the malaria hypothesis, as incidence did not dovetail with swamp locations recorded in the past. The HBB gene mutations for 85 patients were also analyzed. Most prevalent in Halkidiki, Northern Greece, was the codon 39 (C>T) mutation (27.1%) followed by the IVS-I-110 (G>A) mutation (22.4%); this was in direct contrast to the current distribution of the same mutations seen in the rest of Greece (Greek National Genetic Database, GNGD). This frequency inversion was statistically significant, with the difference from the GNGD being 20.6% for the IVS-I-110 mutation (p <0.0005) and 7.6% for the codon 39 mutation (p = 0.0238). The history of Halkidiki, denoting a clear example of geographical isolation from the rest of the country, may possibly account for a potentially diverse genetical identity of the disease in this region.

Effect of HbS in the determination of HbA2 with the Biorad Variant II analyzer.

OBJECTIVES: The effect of the presence of HbS in the determination of HbA2 using the Biorad Variant II analyzer. DESIGN AND METHODS: The effect of HbS presence in the samples was quantified using the HELENA SAS-MX alkaline gel electrophoresis kit as the reference method. RESULTS: The %HbA2 values from the Variant II analyzer and the HELENA SAS-MX alkaline gel electrophoresis kit show a good linear correlation in the absence of HbS. A strong positive bias in the %HbA2 values from the Variant II is apparent in the presence of HbS in the samples, when compared to the alkaline electrophoresis gel. CONCLUSION: The Variant II analyzer gives reliable results for %HbA2 determination when no HbS is detectable in the samples. When HbS is present, the gel electrophoresis method gives more accurate results.

Effect of HbS in the determination of HbA(2) with the TOSOH HLC-723G7 analyzer and the HELENA Beta-Thal Quik column kit.

OBJECTIVES: The analytical performance of the TOSOH HLC-723G7 hemoglobin HPLC analyzer and the effect of the presence of HbS in the determination of HbA(2) using HPLC and manual column methods. DESIGN AND METHODS: The performance characteristics of the TOSOH HLC-723G7 analyzer in the determination of HbA(2) were compared to those of the HELENA Beta-Thal Quik column. The effect of HbS presence in the samples was quantified using the HELENA SAS-MX alkaline gel electrophoresis kit as the reference method. RESULTS: Within-run and between-run CVs for HbA(2) were better for the TOSOH HPLC analyzer than for the HELENA manual column method. The presence of HbS in the samples produces a strong positive bias in the %HbA(2) values when using both the HPLC and manual column methods, compared to the alkaline electrophoresis gel. CONCLUSION: Both the TOSOH HPLC and the manual column are reliable methods for %HbA(2) determination when no HbS is detectable in the samples. When HbS is present, the gel electrophoresis method gives more accurate results.