Phenotype score to grade the severity of thalassemia intermedia

Thalassemia intermedia is an ill-defined group of thalassemia patients with severity in between thalassemia major and asymptomatic carriers. The severity of cases varies greatly. With availability of information about genetic modifiers of beta-thalassemia phenotype, attempts are being made to study genotype phenotype correlation in thalassemia intermedia.

The first important step in genotype, phenotype correlation is well-defined phenotypes. Severity of thalassemia intermedia can not be graded only on haemoglobin level and age of presentation. The authors have developed a phenotype scoring system to subclassify thalassemia intermedia patients into 3 groups, viz, mild, moderate and severe.

This phenotype scoring system appears to grade the severity correctly depending on various clinical features like age of presentation, severity of anaemia, growth retardation, bone marrow hyperplasia, need of blood transfusions and splenectomy.

The classification of thalassemia intermedia will be useful for genotype phenotype correlation, to develop management guidelines for the subgroups and to try new treatment modalities like hydroxyurea, erythropoetin etc.