Background:
Transforming growth factor (tgf)-beta has been shown to be a potent stimulator of collagen production by fibroblasts, and could play a role in the pathogenesis of systemic sclerosis (ssc).
Objective:
To study the possible involvement of tgf-beta1 gene polymorphism in japanese patients with ssc.
Methods:
Fifty-nine patients with ssc and 110 normal subjects were studied. genomic dna was extracted from skin tissues, and was amplified in a thermal cycler, generating a tgf-beta1 gene fragment with a size of 294 bp. the t to c transition at t869c (leu10pro) and the g to c transition at g915c (arg25pro) were identified by digestion with mspa1i and bgli, respectively.
Results:
At t869c (leu10pro), the frequency of the c allele in ssc (65.3%) was significantly higher than in normal controls (50.5%) (p < 0.01). ssc showed c/c allele 42.4%, c/t 45.8% and t/t 11.2%. normal controls showed c/c allele 26.4%, c/t 48.2% and t/t 25.5%. the frequency of the c/c allele in ssc was significantly higher than in normal controls, in comparison with the t/t allele (p < 0.02), but no significant difference was found between the frequency of the c/c allele vs. the c/t allele. the frequency of the c/c allele showed no significant difference between diffuse and limited ssc. at g915c (arg25pro), all the normal controls and ssc patients showed only the g/g allele. these results are different from a previous study in which the frequency of the t/t allele was high in ssc at t869c (leu10pro).
Conclusions:
This discrepancy may indicate that japanese patients with ssc show a different genetic predisposition to tgf-beta1.