CAJ | 학술논문

目的对1个遗传性蛋白C(proteinC,PC)缺陷症家系进行蛋白 C基因(protein C gene,PROC)突变检测,探讨其分子发病机制.方法通过检测先证者及其家系成员(共4代15人)血浆蛋白C活性(protein C activity,PC∶A)、蛋白C抗原含量(protein C antigen,PC∶Ag)及其他凝血指标进行表型分析；用PCR法扩增先证者PROC的9个外显子及其侧翼序列,PCR产物纯化后测序,发现突变位点则反向测序予以证实；针对先证者的突变位点,对其家系成员进行相应基因突变检测.结果先证者PC∶ A和PC∶Ag明显降低,分别为26％和18.60％,家系中其他成员中有7人PC∶A降低,6人PC∶Ag降低.先证者的PROC第7外显子存在g.6128T＞G杂合错义突变导致p.Phe139Val,第9外显子存在g.8478G＞C杂合错义突变导致p.Asp255His；其祖母、父亲、三姑和四姑均存在g.6128T＞G杂合突变,母亲、二舅、妹妹和儿子均存在g.8478G＞C杂合突变.存在g.8478G＞C突变的成员PC∶A下降明显.结论先证者PROCg.6128T＞G和g.8478G＞C突变分别来自其父系家族和母系家族,该复合杂合错义突变是导致遗传性PC缺陷症的分子基础.
목적 대1개유전성단백C(proteinC,PC)결함증가계진행단백 C기인(protein C gene,PROC)돌변검측,탐토기분자발병궤제.방법 통과검측선증자급기가계성원(공4대15인)혈장단백C활성(protein C activity,PC∶A)、단백C항원함량(protein C antigen,PC∶Ag)급기타응혈지표진행표형분석；용PCR법확증선증자PROC적9개외현자급기측익서렬,PCR산물순화후측서,발현돌변위점칙반향측서여이증실；침대선증자적돌변위점,대기가계성원진행상응기인돌변검측.결과 선증자PC∶ A화PC∶Ag명현강저,분별위26％화18.60％,가계중기타성원중유7인PC∶A강저,6인PC∶Ag강저.선증자적PROC제7외현자존재g.6128T＞G잡합착의돌변도치p.Phe139Val,제9외현자존재g.8478G＞C잡합착의돌변도치p.Asp255His；기조모、부친、삼고화사고균존재g.6128T＞G잡합돌변,모친、이구、매매화인자균존재g.8478G＞C잡합돌변.존재g.8478G＞C돌변적성원PC∶A하강명현.결론 선증자PROCg.6128T＞G화g.8478G＞C돌변분별래자기부계가족화모계가족,해복합잡합착의돌변시도치유전성PC결함증적분자기출.
Objective To analyze genetic mutations and explore its molecular pathogenesis for an hereditary protein C (PC) deficiency pedigree.Methods The pedigree has included 15 individuals from 4 generations.Plasma levels of PC activity (PC ∶ A),PC antigen (PC ∶ Ag) and other coagulant parameters were determined for members of the family.The 9 exons and intron-exon boundaries of protein C gene (PROC) of the proband were amplified with PCR and analyzed with direct sequencing.Detected mutations were confirmed with reverse sequencing.Corresponding PCR fragments from the family members were also directly sequenced.Results Plasma PC ∶ A and PC ∶ Ag for the proband was 26％ and 18.60％,respectively,both being lower than normal references.Seven members from the pedigree also had lower PC:A,six had lower PC ∶ Ag.A compound heterozygous missense mutation,including a T＞G transition at position 6128 of exon 7,which results in Phe139Val,and a G＞C transition at position 8478 in exon 9,which results in Asp255His,were identified in the proband.The paternal grandma,father and two aunts were heterozygous for g.6128T＞G,whilst the mother,the second uncle,sister and son were heterozygous for g.8478G＞C.There were lower PC ∶ A in family members with g.8478G＞C.Conclusion The proband had inherited two independent mutations of the PROC gene including g.6128T＞G in exon 7 and g.8478G＞C in exon 9 from her father and mother,respectively.The resulting compound heterozygous mutation has caused a serious hereditary protein C deficiency.