CAJ | 학술논문

目的：采用PCR-高分辨率熔解曲线（HRM）分析筛查成骨不全（OI）一家系患儿（先证者）COL1A1基因突变位点，探讨其基因型与临床表型的联系。方法对先证者进行家族史及临床资料的调查，采集先证者、家属及50名正常对照者血液标本，应用PCR-HRM分析筛查先证者及正常对照者COL1A1基因突变，基因测序确证突变位点。结果先证者COL1A1基因17外显子筛查结果异常，其熔解温度（Tm）值比正常对照者Tm值低约0.4℃。先证者与正常对照者的标准熔解曲线及差异熔解曲线均有明显差异。测序结果为c.1138G>A，突变导致380位氨基酸由甘氨酸（Gly）变成丝氨酸（Ser）：p.（Gly 380 Ser），为错义突变。先证者父亲、祖母均具有相同突变位点。先证者母亲及正常对照者基因测序结果无此突变。该突变在中国人群中未见报道。该家系遗传特征为常染色体显性遗传，先证者临床诊断为Ⅳ型OI，临床表型较严重。结论 PCR-HRM分析是有效的OI基因筛查新方法。COL1A1基因c.1138G>A突变在中国人群中为新发现的突变位点。α螺旋结构域Gly被替换可能导致较严重的临床表型。
목적：채용PCR-고분변솔용해곡선（HRM）분석사사성골불전（OI）일가계환인（선증자）COL1A1기인돌변위점，탐토기기인형여림상표형적련계。방법대선증자진행가족사급림상자료적조사，채집선증자、가속급50명정상대조자혈액표본，응용PCR-HRM분석사사선증자급정상대조자COL1A1기인돌변，기인측서학증돌변위점。결과선증자COL1A1기인17외현자사사결과이상，기용해온도（Tm）치비정상대조자Tm치저약0.4℃。선증자여정상대조자적표준용해곡선급차이용해곡선균유명현차이。측서결과위c.1138G>A，돌변도치380위안기산유감안산（Gly）변성사안산（Ser）：p.（Gly 380 Ser），위착의돌변。선증자부친、조모균구유상동돌변위점。선증자모친급정상대조자기인측서결과무차돌변。해돌변재중국인군중미견보도。해가계유전특정위상염색체현성유전，선증자림상진단위Ⅳ형OI，림상표형교엄중。결론 PCR-HRM분석시유효적OI기인사사신방법。COL1A1기인c.1138G>A돌변재중국인군중위신발현적돌변위점。α라선결구역Gly피체환가능도치교엄중적림상표형。
Objective To investigate COL1A1 gene mutation by PCR-high resolution melting (PCR-HRM) and an-alyze the correlation between genotype and clinical phenotype in a child (proband) with osteogenesis imperfecta (OI). Methods The family history of OI pedigree along with the clinical data was collected. Blood samples from the proband and his family members, as well as 50 normal controls, were collected. The mutation of COL1A1 gene was screened using PCR-HRM and validated by the gene sequence. Results The detection of PCR-HRM showed the abnormal result of COL1A1 17 exon in proband with a lower melting temperature (Tm) value than that of normal controls by 0.4℃. There were signifi-cant differences in the standardization melting curve and the different melting curve between the proband and the normal controls. The sequencing result was c.1138G>A, which meant that cDNA of 1138 base G mutation into A. The mutations transformed the amino acid glycine into a serine at amino acid 380(P. Gly 380 Ser), which resulted in missense mutations. The proband’s father and grandmother had the same mutation of COL1A1 gene. The mutation was not found in the proband’s mother and normal controls. There was no report for such mutation in Chinese population. Pedigree analysis showed the fami-ly genetic characteristics of autosomal dominant inheritance. The proband was clinically diagnosed as OI type Ⅳwith more severe clinical phenotype. Conclusion PCR-HRM analysis is a new effective method for genetic screening of OI. COL1A1 mutation of c.1138G>A is a newly discovered mutation in Chinese population. Gly replaced inαhelical domain may lead to a more severe clinical phenotype.