CAJ | 학술논문

目的鉴定1例火棉胶婴儿转谷氨酰胺酶1基因(transglutaminase 1,TGM1)的致病性突变.方法提取患儿及其父母的外周血DNA,PCR扩增TGM1基因的编码及剪切位点序列,对PCR产物进行直接测序.同时检测100名无血缘关系的正常人作为对照.用TGM1邻近的微卫星标记在家系中构建单倍型以确定突变的来源.应用CLUSTAL X(1.81)软件分析突变氨基酸的跨种属保守性.结果患儿携带了TGM1的两个复合杂合性突变:c.420A＞G (I140M)及c.832G＞A (G278R),均为国际上未报道过的新突变.两个错义突变均造成了TGM1蛋白内高度保守区的氨基酸置换.突变c.420A＞G (I140M)遗传自父亲,位于蛋白的转谷氨酰胺酶N功能域；突变c.832G＞A (G278R)遗传自母亲,位于野生蛋白的转谷氨酰胺酶N功能域和转谷氨酰胺酶样功能域之间.两个突变在100名无血缘关系的正常人中均未发现.结论 c.420A＞G (I140M)和c.832G＞A (G278R)复合杂合性突变为该患儿的致病性突变,本研究结果为该病的诊断提供了分子学依据.
목적 감정1례화면효영인전곡안선알매1기인(transglutaminase 1,TGM1)적치병성돌변.방법 제취환인급기부모적외주혈DNA,PCR확증TGM1기인적편마급전절위점서렬,대PCR산물진행직접측서.동시검측100명무혈연관계적정상인작위대조.용TGM1린근적미위성표기재가계중구건단배형이학정돌변적래원.응용CLUSTAL X(1.81)연건분석돌변안기산적과충속보수성.결과 환인휴대료TGM1적량개복합잡합성돌변:c.420A＞G (I140M)급c.832G＞A (G278R),균위국제상미보도과적신돌변.량개착의돌변균조성료TGM1단백내고도보수구적안기산치환.돌변c.420A＞G (I140M)유전자부친,위우단백적전곡안선알매N공능역；돌변c.832G＞A (G278R)유전자모친,위우야생단백적전곡안선알매N공능역화전곡안선알매양공능역지간.량개돌변재100명무혈연관계적정상인중균미발현.결론 c.420A＞G (I140M)화c.832G＞A (G278R)복합잡합성돌변위해환인적치병성돌변,본연구결과위해병적진단제공료분자학의거.
Objective To identify potential mutations in a Chinese collodion baby.Methods The patient was investigated clinically.DNA was extracted from peripheral blood of the baby and his parents.All coding exons (exons 2-15) and splicing sites of transglutaminase 1 (TGM1) were amplified by polymerase chain reaction (PCR).Mutation detection was performed by directed sequencing of the PCR products.A total of 100 healthy unrelated subjects were used as controls.Haplotypes were constructed with microsatellites flanking the locus,and TGM1 genotypes of the family were used to determine parental origins of the mutations.CLUSTAL X (1.81) was employed to analyze cross-species conservation of the mutant protein sequence. Results The boy was found to be a compound heterozygote for two novel mutations:c.420A＞G (I140M) from his father and c.832G＞A (G278R) from his mother,with the former occurring in the transglutaminase N domain and the latter between transglutaminase N and transglutaminase-like domains.Both mutations were absent from the control subjects.Conclusion The boy's condition was caused by two novel compound heterozygous mutations of c.420A＞G and c.832G＞A of TGM1.Author's results may provide new clues for molecular diagnosis of this disease.