Rapid Detection of β-Globin Gene Mutations and Polymorphisms by Temporal Temperature Gradient Gel Electrophoresis

Abstract

Background: Inherited hemoglobin disorders represent the most common Mendelian disease worldwide. Prevention programs based on molecular diagnosis of heterozygous carriers and/or patients require the use of reliable mutation scanning methods in at-risk populations. Methods: We developed a rapid and highly specific mutation-screening test based on temporal temperature gradient gel electrophoresis (TTGE). We analyzed 889 β-thalassemia genes from homozygous β-thalassemia patients and unrelated individuals with heterozygous β-thalassemia. Previously reported common mutations were screened by reverse dot blots using allele-specific probes. The rare mutations were analyzed by TTGE. Results: We found common mutations in 753 β-thalassemia genes. TTGE analysis in the rest of the genes showed the presence of mutations in different regions of the β-globin gene in 134 of them, and these mutations were characterized by DNA sequencing. In the two genes in which mutations were not identified, large deletions spanning β-globin gene were suspected. Conclusions: Compared with other approaches for comprehensive mutation screening, the reported method is rapid, highly sensitive, cost-effective, and suitable for high-throughput screening of a large number of samples.