Challenges in Thalassemia diagnosis

Thalassemia is typically caused by sequence variants in the HBA1, HBA2 or HBB genes. The common sequence variants include a wide range of sequence variants, such as Single Nucleotide Variants (SNVs), smaller insertion and deletions (Indels) as well as large, exon spanning Copy Number Variations (CNVs). A range of different techniques such as GAP-PCR, Sanger sequencing, reverse hybridisation and MLPA is traditionally required to assess all variants.

Testing for both Alpha Thalassemia and Beta Thalassemia can be a complex process. Workflows are laboratory specific and often require the use of several different techniques to obtain a result. Relying on a patchwork of methods presents challenges such as:

• Long turn-around times to get an overview of both alpha and beta thalassemia sequence variants in a patient
• Resource-intensive and costly processes to validate, maintain and train operators on all assay types
• Risk that sequence variants remain undetected if the workflow is terminated when a first sequence variant is found, or a method is used where only sequence variant-specific detection is possible
• Risk for sample contamination and mix-up when handling multiple tubes and protocols