HMOX1 promoter (GT)n polymorphism is associated with childhood-onset systemic lupus erythematosus but not with juvenile rheumatoid arthritis in a Mexican population

作者：Cordova E J; Martinez Hernandez A; Ramirez Bello J; Velazquez Cruz R; Centeno F; Baca V; Orozco L^*

来源：Clinical and Experimental Rheumatology, 2012, 30(2): 297-301.

• HMOX1
• polymorphism
• paediatric SLE
• arthritis

Objectives
The heme oxigenase 1 (HO-1), a rate-limiting enzyme for heme degradation, is an important cytoprotective protein. Transcriptional activity of HO-I coding gene (HMOX1) can be regulated by the presence of a dinucleotide repeat polymorphism (GT)n at its promoter region. Accordingly, length of (GT)n repeat has been associated with susceptibility to several diseases. We investigated whether the HMOX1 (GT)n polymorphism was associated with childhood-onset systemic lupus erythematosus (SLE) and juvenile rheumatoid arthritis (IRA) susceptibility.
Methods
We studied 207 and 333 unrelated Mexican patients with IRA and childhood-onset SLE, respectively. The control population consisted of 653 individuals ethnically matched with cases. The HMOX1 (GT)n polymorphism was genotype by PCR and fluorescence technology.
Results
We found 27 different alleles, with the 22 and 29 repeats as the most common alleles. Distribution of short allele (n<25) and SS genotype was not statistically associated with IRA subjects. Interestingly, the frequency of both short allele and SS genotype was significantly associated with SLE susceptibility (OR=1.47, 95%CI [1.14-1.89], p=0.002; and OR=2.79, 95%CI [1.24-6.24], p=0.01, respectively).
Conclusion
The distribution pattern of HMOX1 (GT) alleles was different in the Mexican population than those reported elsewhere. Our results suggest that HMOX1 (GT)n polymorphism was associated with susceptibility to childhood-onset SLE but not with IRA in Mexican individuals.

• 出版日期2012-4