SNPscan Combined With CNVplex as a High-Performance Diagnostic Method for Thalassemia

Area of Science:

• Genetics and Molecular Biology
• Hematology
• Public Health

Background:

• Thalassemia is a serious Mendelian-inherited blood disorder with significant public health implications, necessitating advanced diagnostic tools.
• Current diagnostic methods for thalassemia require enhancement to meet the growing need for precision and accuracy in identifying diverse mutations.

Purpose of the Study:

• To introduce and evaluate two novel molecular diagnostic techniques, SNPscan and CNVplex, for the precise identification of thalassemia mutations.
• To assess the accuracy and reliability of SNPscan/CNVplex compared to traditional diagnostic methods in a large cohort.

Main Methods:

• SNPscan utilizes allele-specific probes and PCR product length variations to detect single nucleotide polymorphisms across 67 loci.
• CNVplex identifies deletional mutations by analyzing probe positions within the globin gene, capable of detecting six distinct deletions.
• Methodologies were validated in a training cohort (100 individuals) and a large validation cohort (1647 patients, 100 controls) via a double-blind study against traditional techniques.

Main Results:

• The SNPscan/CNVplex assay accurately identified 10 known mutations in the training set, consistent with traditional methods.
• In validation, SNPscan/CNVplex achieved 100% accuracy, surpassing traditional methods (99.43%) and detecting three previously unidentified mutations in 10 cases.
• Three novel mutations were discovered: two deletion types (Chinese Gγ(Aγδβ)0 del and SEA-HPFH) and one non-deletion type (Hb Q-Thailand).

Conclusions:

• The SNPscan/CNVplex assay provides a highly accurate, reliable, and cost-effective tool for molecular diagnosis of thalassemia.
• These user-friendly assays demonstrate significant potential for widespread clinical application as a primary diagnostic method for thalassemia.