Decoding thalassemia and sickle cell disease: advances in molecular technologies for comprehensive variant detection

Abstract

Thalassemia and sickle cell disease are inherited hemoglobinopathies caused by pathogenic variants in the globin genes and represent a major global health burden. Despite major advances in screening and diagnostics, challenges persist due to extensive genetic heterogeneity and complex genotype-phenotype relationships. Conventional workflows typically combine hematologic and biochemical analyses with targeted DNA-based testing. However, traditional molecular approaches are often sequential and labor-intensive, with limited capacity to detect the full spectrum of pathogenic variation. Advances in next-generation sequencing (NGS) now enables integrated and comprehensive strategies to support hemoglobinopathy diagnostics and screening follow-up. Currently available NGS-based platforms allow simultaneous detection of diverse variant classes, including sequence variants and copy number alterations, across multiple disease-relevant genes, including genetic modifiers that may influence disease severity. This review summarizes the genetic basis of thalassemia and sickle cell disease and compiles traditional and emerging molecular testing methodologies. It further discusses the strengths, limitations and utility of NGS-based platforms, and considers their role in shaping future screening and diagnostic workflows for hemoglobinopathies.