浙江省815例白癜风患者遗传流行病学研究

目的探讨白癜风可能的遗传模式。方法通过调查表得到浙江地区815例白癜风患者及其一、二级亲属的数据。815例白癜风患者中男411例（50．43％），女404例（49．57％），年龄2月龄至71岁。由于缺乏当地白癜风患病率普查数据，因此设立对照组以方便遗传模式及遗传度的计算。468名对照组性别及各年龄段比例与病例组具有可比性。应用Penrose法、Falconer回归法及SAGE—REGTL软件对白癜风患者进行遗传方式分析，遗传度计算及复合分离分析。结果所调查的815例白癜风先证者中，有家族史者128例，无家族史者687例，遗传率15．70％。Penrose法计算出同胞患病率（s）／人群患病率（q）为41．76，不接近1／2q（260．42），也不接近1／4q（130．21），而接近1／√q（22182），提示白癜风符合一种多基因遗传模式。白癜风患者一、二级亲属遗传度分别为59．61％和55．20％，加权遗传度为58．7％。复合分离分析显示孟德尔显性、隐性、加性主基因模型假设均被接受；单纯环境与非传递模型被拒绝；以AIC值判断，显性模型拟合程度最好。结论遗传因素在白癜风发病中占有重要作用，白癜风符合一种多基因或多因子遗传模式，存在主基因效应。

Study on genetic epidemiology on 815 patients with vitiligo in Zhejiang area

Objective Genetic factors are thought to be involved in the development of vitiligo. The aim of this study is to explore the possible genetic model of vitiligo by analyzing the genetic characteristics of 815 patients from Zhejiang province. Methods Data for 815 patients with vitiligo together with their first-and second-degree relatives were obtained using a standardized questionnaire. All these information was requested to confirm the answers about family history in order to reduce the possibility of 'recall' bias. The 815 probands would include 411(50.43%) males and 404(49.57%) females with a varied age from 2 months to 71 years old. Since the information on general prevalence of vitiligo in this area was absent, a control group was set up to facilitate the calculations of heritabillty degree. 468 persons of the control group were from non-vitiligo population with a sex ratio of 241(male): 227(female) with varied age of 4 months to 80 years old. Both gender and age were comparable between the vitiligo and the control population. The inheritance pattern estimation, heritabillty calculation and complex segregation analysis were performed with Penrose method, Falconer regression method and SAGE-REGTL program. Results In 815 vitiligo probands, 128 had and 687 had not family histories, with a heritability rate of 15.7%. The vitiligo prevalence in proband's first degree relatives was 2.580%, higher than the prevalence of 0.618% in second degree relatives, and both of them were higher than general prevalence: 0.192%. By Penrose method, the rates on different catagories were as follows: sibling prevalence rates s = 0.080 18; population prevalence rate q=0.001 92; s/q =41. 76. The ratio of s/q did not approach 1/2q (260.42) or 1/4q (130.21), but approached 1/(?) (22.82), suggesting vitiligo was consistent with a mode of polygenic inheritance. Using Falconer's method, heritabilities of vitiligo in first-and second degree relatives of probands were 59.61% (95% confidence interval 65.37-53.84) and 55.20% (95% confidence interval 43.88-66.52), respectively. The weighted average of heritabillty in all relatives was 58.7% (95% confidence interval 53.56-63.83). The results of complex segregation analysis suggested that major gene model including the Mendelian dominant, recessive and additive hypotheses were not rejected (P>0.05). Purely environmental model and no transmission model were rejected at a 0. 001 significance level. According to AIC, Mendelian dominant inheritance was the best-fitted hypothesis. Conclusion Genetic factors played an important role in the occurrence of vitiligo, and the genetic model of vitiligo could serve as the polygenetic or multifactorial inheritance with major gene trait.