[The relationship between RUNX3 gene mutation and keloid]

To study the mutation in RH120480 fragment of RUNX3 gene among the Chinese patients with keloid.

20 samples of keloids were collected with each patient's venous blood sample as normal control group. The genomic DNA was extracted from each sample. RH120480 fragment of RUNX3 gene was amplified by Polymerase Chain Reaction (PCR). The amplification products were analyzed by denaturing high-performance liquid chromatography (DHPLC). Some fragments were sequenced directly and then compared with the GenBank data.

By DHPLC, the results of all the blood samples showed single chromatographic peak indicating homoduplexes, meanwhile the results of keloid tissue samples showed double peak indicating heteroduplexes. Through gene sequencing, 19 cases showed gene mutation among the 20 samples of keloid. The mutation incidence was 95%. Two mutation sites were detected including base A absence in 96th sites and base C insert in 279th sites. The base A absence rate was 90% (18/20) in keloid group, and 10% (2/20) in control group. The base C insert mutation rate was 95% (19/20) in keloid group, and 0% (0/20) in control group. There was significant difference in the mutation rate between two groups on the two mutation sites.

There is a strong correlation between the RH120480 fragment of RUNX3 gene mutation and Keloid. RUNX3 gene could be possibly a scar suppressor gene (SSG).