Molecular Heterogeneity of -Thalassemia Alleles in Spain and its Importance in the Diagnosis and Prevention of -Thalassemia Major and Sickle Cell Disorders

In the last 20 years, migratory flows have changed the pattern of -thalassemia (-thal) mutations in Catalonia and have also increased S prevalence, either alone or in association with -thal alleles. Characterization of the gene is needed for genetic counseling for -thal major and also for sickle cell diseases. The purpose of this study was to investigate the current distribution pattern of -thal mutations. Seventy nine individuals were characterized at the molecular level. As a first step, frequent mutations in the Mediterranean region were screened and when none of these mutations were identified, the -globin gene was sequenced. Screening for common mutations allowed the characterization of 60 individuals. In the remaining 19 cases, 11 different mutations were identified. -Thalassemia heterogeneity in Spain has markedly increased, leading to the requirement of including new methods for genetic diagnosis. Prevention of -thal major and sickle cell disease are necessary since their prevalence in Spain is increasing dramatically.