Genotype-phenotype analysis in HbS-beta-thalassemia

Genotypes and phenotypes were studied in 31 Turkish HbS-beta-thalassemia patients. In 19 patients the beta-thalassemia mutations were beta(+) and in 12 the beta(0) phenotype. The IVSI-110 mutation was found in 45% of the patients. IVSI-1, beta 39, IVSII-1 and FSC8 are the genotypes associated with beta(0)-thalassemia. Hematological data were evaluated at the time of diagnosis and 4 years after diagnosis. The mean HbF value was 13 +/- 7.8% at diagnosis and 9.7 +/- 7.8% 4 years later. A significant negative correlation was observed between the age of the patients and the HbF value (p < 0.05). No statistically significant differences were observed between the mean of hematological parameters in beta(+)- and beta(0)-thalassemia patients except for the mean HbF value which were 10.7 +/- 6.9 and 15.9 +/- 7.7% in beta(+)- and beta(0)-thalassemia, respectively (p < 0.05), The study indicated that beta-thalassemia mutations in trans to the HbS mutation do not exert any beneficial effect on the manifestation of the disease.