甘露糖结合凝集素基因点突变与风湿性心脏病易感性的关系

目的探讨风湿性心脏病易感性与甘露糖结合凝集素基因第一外显子点突变的关系.方法采用PCR和限制性片段长度多态性分析对36例慢性风湿性心脏病病人和39名正常人的甘露糖结合凝集素(MBL)等位基因分布情况进行分析.结果风湿性心脏病病人及正常人均未发现有MBL C和D等位基因的出现;11例病人为MBL A/B等位基因杂合子,1例病人为MBL B/B等位基因纯合子;15名正常人为MBL A/B等位基因杂合子,未发现有MBL B/B等位基因纯合子.携带B等位基因的风湿性心脏病病人平均症状出现年龄为30岁±14岁,AA纯合子病人的平均症状出现年龄为37岁±11岁,差异有显著意义(P<0.05).结论甘露糖结合凝集素基因的点突变所造成的甘露糖结合凝集素功能低下或血清浓度偏低,可能不是风湿性心脏病发病的主要原因,但会加速风湿性心脏病的进展,这与风湿性心脏病易感人群在青少年中最高是一致的.

Mannose-binding lectin gene site mutations and the susceptibility of rheumatic heart disease

OBJECTIVE: To investigate the relationship between mannose-binding lectin(MBL) gene exon 1 site mutations and chronic rheumatic heart disease (CRHD). METHODS: Polymerase chain reaction (PCR) and restrictive fragment length Polymorphism (RFLP) were used to investigate the MBL exon 1 alleles in 36 patients with CRHD and 39 normal people. RESULTS: No C and D alleles of MBL gene were found in both groups. Eleven patients had A/B alleles, 1 patient had B/B alleles, 15 normal people had A/B alleles but none of the 39 normal people had B/B alleles. Statistic analyses showed no significant difference between CRHD group and normal group. But when the age of heart-disease-symptom-onset (HDSO) of the CRHD group were considered, we found that the mean HDSO age of patients with B allele was 30 +/- 14 years and the mean HDSO age of patients with AA homozygous was 37 +/- 11 years. P < 0.05. CONCLUSION: MBL gene mutations may not be a main factor of the pathogenesis of CRHD, but MBL deficiency may facilitate the development of CRHD in younger people and accelerate the progress of CRHD. This is consistent with the phenomenon that the most susceptible people of rheumatic heart disease are teenagers.