OBJECTIVETo investigate the pathogenesy deference between multiple and single site keloid by detecting gene mutation of Poly A site of transforming growth factor-beta1 receptor type II (TbetaR II).

METHODSCollecting 20 keloid samples (6 multiple sites keloid samples and 14 single site keloid samples) and extracting DNA from them; designing and synthesizing the primers of Poly A site, then amplifying T1beta II DNA by PCR, analyzing the single strand conformation polymorphism about the products of PCR. After purifying the product of PCR, the site and type of the mutation rate of Poly A site was sequenced directly on the automatic sequencing equipment.

RESULTSIt had been found that the Poly A site of TbetaR II in keloid has deletion mutation, its mutation rate in multiple sites keloid was 50% (3/6), in single site keloid 7.1% (1/14). The mutation rate of Poly A site in multiple sites keloid was significant higher than that in single site keloid (P < 0.05)

CONCLUSIONIt has been supposed that there are some deference in pathogenesy between the multiple and the single site keloid.