先天性肾性尿崩症患者精氨酸加压素受体2基因突变的检测分析

目的　探讨并检测先天性尿崩症患者精氨酸加压素受体 2 (AVPR2 )基因突变的临床意义。方法　对临床诊断为先天性尿崩症的 7例患者及 2 4名亲属的血液样本 ,提取基因组DNA ,通过PCR扩增AVPR2基因的 6个片断 ,用单链构象多肽性 (SSCP)进行基因突变的筛查 ,再对异常条带进行DNA测序证实基因的突变。结果　在 7例先天性尿崩症的患者中 ,发现 6例患者存在 5种类型共8个AVPR2的突变点 ,2例患者有AVPR2基因的双点突变 ,其余为单突变点 ,1例患者的母亲为AVPR2基因突变的携带者。其中 4个突变点国际尚未报道 ,它们分别是 :G 4 6 9 4 93del 2 4 ,G 5 4 1insT ,G 4 6 2delC和G 935T >C ,分别导致AVPR2受体蛋白A37 L4 4del(缺失突变 ) ,A6 1G 190X(插入移码突变 ,无义突变 ) ,P34R 36X(缺失移码突变和无义突变 ) ,C192R(错义突变 )。结论　发现了 4种新的AVPR2基因突变类型。采用PCR SSCP的方法可以对尿崩症的患者进行基因突变的粗筛 ,最后经过DNA测序可以做出基因突变的诊断。

Identification of mutations in the arginine vasopressin receptor 2 gene in congenital nephrogenic diabetes insipidus patients

Objective To investigate the mutations of arginine vasopressin receptor 2 (AVPR2) gene in congenital nephrogenic diabetes insipidus (NDI) patients Methods Genomic DNA was extracted from the blood samples of 7 congenital NDI patients, all males, and 24 of their family members The 6 fragments of AVPR2 gene were amplified by PCR The gene mutations were preliminarily screened by SSCP and further confirmed by DNA sequencing Results 5 types of mutation and 8 mutant sites of AVPR2 gene were found in 6 of the 7 patients Two cases were found to have 2 different sites of mutation in the AVPR2 gene In 4 cases new mutation sites not reported previously in the literature, i e , g 469 493del 24,g 541insT,g 462delC and g 935T>C, were identified, resulting in the change of AVPR2 proteins, including A37 L44del (deletion mutation), A61G 190X(insertion frame shift and nonsense mutation), P34R 36X(deletion frame shift and nonsense mutation)and C192R (missense mutation) Among the 24 family members examined only one, a mother, was found to have an AVPR2 gene mutation with the same mutation site as the proband Conclusion Four novel mutation sites have been identified in the AVPR2 gene among the congenital NDI patients PCR SSCP and DNA sequencing can be used to preliminarily screen and diagnose gene mutation among congenital NDI patients