家族性重症肌无力与HLA-DQB1等位基因多态性的相关性

目的探讨中国北方地区家族性重症肌无力（myasthenia gravis，MG）与HLA-DQB1等位基因多态性的相互关系。方法应用聚合酶链反应．序列特异性引物方法对中国北方地区15例家族性MG、49例散发性MG和51名健康对照组的HLA-DQB1基因多态性进行分析。结果在家族性MG中DQB1＊0501等位基因频率明显高于散发MG（P〈0．05，OR：3．08）和对照（P=0．001，OR=4．439），尤其是眼型患者更加显著有统计学意义（P〈0．01，OR=7．67）。结论DQB1＊0501等位基因是家族性MG尤其是眼型患者的易感基因；遗传因素与重症肌无力发生密切相关。家族性MG有其独特的临床特点。

HLA-DQB1 allele polymorphism and clinical characteristics of 15 familial myasthenia gravis cases in north China

Objective To investigate the relationship between the HLA-DQB1 allele polymorphisms and the clinical features of 15 familial myasthenia gravis (MG) cases in north China. Methods By polymerase chain reaction-sequence specific primers(PCR-SSP), the HLA-DQB1 gene polymorphisms were determined in 64 MG patients (15 familial and 49 sporadic) and 52 healthy individuals as control group. The clinical characteristics of 15 familial MG patients and 49 sporadic were analyzed. The measurement data was analyzed by t test and enumeration data by Chi-square test. Results The frequency of DQB1*0501 was significantly increased in familial MG, especially in the ocular type, compared with sporadic MG (P<0.05,OR=3.08) and healthy controls(P<0.01,OR=4.439). Comparing with healthy controls, the frequency of DQB1*0301/4 was increased (P<0.05, OR=2.56), while the frequency of DQB1*0601 was significantly decreased (P<0.05, OR=0.33) in sporadic MG. The familial patients had an early age of disease onset, but less severity and good prognosis. Conclusion The familial MG has distinctive clinical features. DQB1*0501 allele is positively related to the genetic susceptibility to familial MG patients in north China, especially to the ocular type. DQB1*0301/4 allele is positively related to the pathogenesis of sporadic MG. DQB1*0601 may be a protecting allele for sporadic MG. The phenotype of MG may be the result of interaction of hereditary defects and environmental factors. The familial MG may be different from sporadic patients in genetic immune mechanism.