[Relationship between mutation at 1 573 fragment of TNF receptor II gene and keloid].

ABSTRACT

OBJECTIVE: To study the mutations at 1 573 fragment of TNF receptor II (TNFR-II) gene in patients with keloid. METHODS: The tissue DNA was extracted from 22 samples of keloids donated by 22 patients (6 males and 16 females, aged 18-53 years), and all keloids were examined and classified by pathologist. The peripheral blood DNA was extracted from the same patients as the control. PCR was used to amplify the 1 573 fragment of TNFR-II gene from the keloid tissue DNA and peripheral blood DNA. The PCR products were sequenced directly and then compared with the GeneBank data. RESULTS: All the concentration of the extracted DNA in trial were higher than 0.50 microg/microL and the purity (A260/A280) of the extracted DNA were higher than 1.5. It closed to the magnitude of the design DNA fragment by agarose gel electrophoresis examining, and corresponded with the test requirement. Mutations at 1 573 fragment of TNFR-II gene were detected in 13 out of 22 keloids. The mutation incidence was 59.1%. Among them, 9 had point mutation at codon 1 663, accounting 40.9%. No TNFR-II gene mutation was detected in all peripheral blood samples. There were significant difference between keloids DNA and peripheral blood DNA (P < 0.01). The mutations involved point mutation, deletion and insertion as well as multisite and multitype. CONCLUSION: There is a correlation between the mutation at 1 573 fragment of TNFR-II gene and keloid.