Immunogenetic Transplant Laboratory, Department of Clinical Pathology, Faculty of Medical Sciences, University of Campinas, Campinas, Brazil.
Int J Dermatol. 2010 Oct;49(10):1133-40. doi: 10.1111/j.1365-4632.2010.04465.x.
The strongest genetic marker for psoriasis is Cw*06. Polymorphisms in the tumor necrosis factor (TNF)-alpha promoter region, especially replacement of guanine with adenine in positions -238 and -308 are related to higher TNF-alpha production and higher risk for psoriasis in Caucasoid populations, not found in Asians. We performed a case-control study of 69 patients with psoriasis type I and 70 controls, characterized clinical progression along 10-years of follow-up in mild or severe disease and determined HLA class I, II, and TNF single nucleotide polymorphisms (SNPs) -238 and -308 polymorphisms to demonstrate whether these polymorphisms may be genetic risk for susceptibility to psoriasis or severity of the disease in Brazilians.
Polymorphisms were identified using PCR/SSP. Alleles, genotypes, and haplotypes frequencies were compared using Fisher's test.
More severe disease was found in male patients. It may be suggested that alleles B37, Cw06, Cw12, and DRB107 were associated with severe disease course, while B*57 with mild disease. No statistical difference was found between the patients and controls regarding polymorphisms frequencies in TNF SNPs. This study pointed to a higher TNF-238 G/G genotype frequency (OR: 3.21; CI: 1.06–9.71; P = 0.04) in the group with severe disease.
Polymorphisms in the TNF-alpha SNPs do not seem to be a more important genetic risk factor for psoriasis than the already known Cw*06 in Brazilian patients, but these markers may be related to clinical manifestations.
银屑病最强的遗传标志物是 Cw*06。肿瘤坏死因子（TNF）-α启动子区域的多态性，特别是位置-238 和-308 的鸟嘌呤被腺嘌呤取代，与高加索人群中 TNF-α产生增加和银屑病风险增加有关，但在亚洲人群中未发现。我们对 69 例 1 型银屑病患者和 70 例对照者进行了病例对照研究，对轻或重度疾病的 10 年随访过程中的临床进展进行了特征描述，并确定了 HLA Ⅰ类、Ⅱ类和 TNF 单核苷酸多态性（SNP）-238 和-308 多态性，以证明这些多态性是否可能是银屑病易感性或疾病严重程度的遗传风险因素。
使用 PCR/SSP 确定多态性。使用 Fisher 检验比较等位基因、基因型和单倍型频率。
男性患者的疾病更严重。这可能表明等位基因 B37、Cw06、Cw12 和 DRB107 与严重疾病过程相关，而 B*57 与轻度疾病相关。TNF SNP 多态性在患者和对照组之间的频率无统计学差异。本研究表明 TNF-238 G/G 基因型频率（OR：3.21；CI：1.06–9.71；P = 0.04）在严重疾病组中较高。
TNF-α SNP 多态性似乎不是比已知的巴西患者 Cw*06 更重要的银屑病遗传风险因素，但这些标志物可能与临床表现有关。
