Shi-Ping Cai

Identification of the multiple beta-thalassemia mutations by denaturing gradient gel electrophoresis.

We used denaturing gradient gel electrophoresis to detect the beta-thalassemia mutations in the Chinese population. By amplifying the beta-globin gene in four separate fragments and electrophoresing the amplified DNA in two gels, we were able to distinguish all the 12 known mutations on the basis of the mobility of the homoduplexes and heteroduplexes. We conclude that denaturing gradient gel electrophoresis offers a nonradioactive means of detecting multiple mutations in genetic disorders.

Molecular basis of β thalassemia in South China

SummaryThe phenotype of β thalassemia can be caused by over 40 different mutations. To set up a prenatal diagnosis program using DNA analysis, it is important to determine the type and frequency of mutation in a particular geographic area. We have delineated the molecular lesions that cause β thalassemia in the Guangdong province of China, and found six mutations in four different haplotypes. The surprising finding that five of these mutations each occur in two different haplotypes suggests the occurrence of crossing over or gene conversion events at the β-globin locus. The delineation of the haplotypes and mutations will permit the choice of the appropriate probes for prenatal detection of β thalassemia in this part of China.