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

Abstract

In the last 20 years, migratory flows have changed the pattern of β-thalassemia (β-thal) mutations in Catalonia and have also increased β^S prevalence, either alone or in association with β-thal alleles. Characterization of the β gene is needed for genetic counseling for β-thal major and also for sickle cell diseases. The purpose of this study was to investigate the current distribution pattern of β‐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 β-globin gene was sequenced. Screening for common mutations allowed the characterization of 60 individuals. In the remaining 19 cases, 11 different mutations were identified. β-Thalassemia heterogeneity in Spain has markedly increased, leading to the requirement of including new methods for genetic diagnosis. Prevention of β-thal major and sickle cell disease are necessary since their prevalence in Spain is increasing dramatically.

Keywords:

• β-Thalassemia (β-thal)
• Sickle cell disorders
• Molecular heterogeneity
• Prenatal diagnosis