Optimization and application of a dried blood spot-based genetic screening method for thalassemia in Shenzhen newborns.

BACKGROUND: To optimize and apply an approach suitable for large-scale neonatal thalassemia genetic screening in China, thalassemia genotypes were determined by polymerase chain reaction-reverse dot blot using DNA extracted from dried blood spots (DBS) obtained from newborn screening programs.

METHODS: Firstly, the most suitable commercial DNA extraction kit for DBS was screened. Then, the appropriate amount of DBS required for the automated high-throughput DNA extraction system was evaluated. Finally, the thalassemia prevalence and genotype spectrum in Shenzhen were investigated in 2028 newborns using the optimized screening procedure.

RESULTS: The Magentec extraction kit was best suited for the automated DBS DNA extraction system using eight 3-mm DBS discs. The neonatal thalassemia prevalence in Shenzhen was 9.12%; 6.31% α-thalassemia, 2.37% β-thalassemia, and 0.44% α-/β-thalassemia.

CONCLUSIONS: Genetic screening based on DBS can precisely identify the thalassemia genotypes. Both α- and β-thalassemia are widely distributed in Shenzhen newborns. Newborn genetic screening is important for establishing a comprehensive thalassemia prevention program and for public education.