CAJ | 학술논문

目的研究中国人Noonan综合征患者非受体型蛋白酪氨酸磷酸酯酶(protein-tyrosine phosphatase,nonreceptor-type 11,PTPN11)基因的突变.方法收集遗传咨询门诊3例散发的Noonan综合征患者及其无症状父母,外周血提取基因组DNA,PCR产物直接测序法对患者PTPN11基因的全部15个编码区外显子及其邻接的内含子区域进行测序,检出突变后再对其父母的相应外显子区域进行测序,并通过限制性内切酶检测100名无亲缘关系的正常人相应碱基改变以排除多态性,利用网上ClustalW工具分析突变位点所在氨基酸在多个物种中的保守性.结果在1例患者的第3外显子区域检出一杂合的c.181G＞A碱基取代,导致第61位的天冬氨酸改变为天冬酰胺(p.D61N),在其无症状父母和100名正常个体中无此突变;该位点在多个物种中高度保守.另外2例患者PTPN11基因的编码区未检到突变.结论 p.D61N突变在文献中已有报道,本例患者为新生突变.本研究进一步肯定了 p.D61N为Noonan综合征的致病突变,基因诊断的结果验证了该患者的临床诊断.另外两例Noonan综合征患者可能由其他基因的突变所致,反映了该病的遗传异质性.
목적 연구중국인Noonan종합정환자비수체형단백락안산린산지매(protein-tyrosine phosphatase,nonreceptor-type 11,PTPN11)기인적돌변.방법 수집유전자순문진3례산발적Noonan종합정환자급기무증상부모,외주혈제취기인조DNA,PCR산물직접측서법대환자PTPN11기인적전부15개편마구외현자급기린접적내함자구역진행측서,검출돌변후재대기부모적상응외현자구역진행측서,병통과한제성내절매검측100명무친연관계적정상인상응감기개변이배제다태성,이용망상ClustalW공구분석돌변위점소재안기산재다개물충중적보수성.결과 재1례환자적제3외현자구역검출일잡합적c.181G＞A감기취대,도치제61위적천동안산개변위천동선알(p.D61N),재기무증상부모화100명정상개체중무차돌변;해위점재다개물충중고도보수.령외2례환자PTPN11기인적편마구미검도돌변.결론 p.D61N돌변재문헌중이유보도,본례환자위신생돌변.본연구진일보긍정료 p.D61N위Noonan종합정적치병돌변,기인진단적결과험증료해환자적림상진단.령외량례Noonan종합정환자가능유기타기인적돌변소치,반영료해병적유전이질성.
Objective To investigate the mutations in protein tyrosine phosphatase, nonreceptor-type 11 (PTPN11)gene in patients with Noonan syndrome (NS). Methods Three sporadic patients with NS were studied. Genomic DNAs were extracted from peripheral blood leukocytes. All 15 coding exons and their flanking intronic boundaries of the PTPN11 gene were amplified by polymerase chain reaction and followed by direct sequencing. DNAs from parents were sequenced in the corresponding region when the mutation was detected in their affected child. The identified mutation was screened in 100 healthy individuals for exclusion of polymorphism by restriction endonuclease digestion of the PCR products. Protein conservation analysis was performed among 10 species using an online ClustalW tool. Results Direct DNA sequence analysis identified a heterozygous 181G to A change in exon 3 of the PTPN11 gene in one patient,which resulted in the substitution of an aspartic acid residue by an asparagine at codon 61. The mutation was absent in his parents and 100 controls, and is located in a highly conserved amino acid site. No mutation in the coding region of PTPN11 gene was observed in the other two patients. Conclusion The p. D61N mutation was reported previously in Caucasians and is a de-novo mutation in this patient. Our study further confirmed that the p. D61N is a pathogenic mutation for NS and consistent with the clinical diagnosis.Additional genes may be involved in the other two patients with NS, indicating high genetic heterogeneity of this disease.