[PCR products with heterozygous mutations containing two types of heteroduplexes].

OBJECTIVE: To confirm that PCR products with heterozygous mutations contain not only wide-type and mutant homoduplexes, but also two types of heteroduplexes. METHODS: An insertion-deletion mutation in the exon 1 of KRT9 gene (497delAinsGGCT), which caused Chinese epidermolytic palmoplantar keratoderma (EPPK) was investigated by polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE) and denaturing high-performance liquid chromatography(DHPLC). RESULTS: Two heteroduplexes and two homoduplexes in the PCR product from the heterozygous mutation of the exon 1 of KRT9 (497delAinsGGCT) were detected. CONCLUSION: PCR products from KRT9 gene with heterozygous mutations contain two types of heteroduplexes. It is without the need to perform heating and cooling PCR products obtained from heterozygous mutations in advance before the mutation screening steps such as denaturing gradient gel electrophoresis (DGGE), temperature gradient gel electrophoresis (TGGE), conformation-sensitive gel electrophoresis (CSGE), DHPLC and heteroduplex analysis (HA), etc.