Rapid detection of beta-globin gene mutations and polymorphisms by temporal temperature gradient gel electrophoresis

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.

We developed a rapid and highly specific mutation-screening test based on temporal temperature gradient gel electrophoresis (TTGE). We analyzed 889 beta-thalassemia genes from homozygous beta-thalassemia patients and unrelated individuals with heterozygous beta-thalassemia. Previously reported common mutations were screened by reverse dot blots using allele-specific probes. The rare mutations were analyzed by TTGE.

We found common mutations in 753 beta-thalassemia genes. TTGE analysis in the rest of the genes showed the presence of mutations in different regions of the beta-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 beta-globin gene were suspected.

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.