CAJ | 학술논문

目的对X-连锁无丙种球蛋白血症(XLA)家系进行致病基因突变分析及产前诊断.方法收集2011年1月至2012年6月在郑州大学第一附属医院就诊的3个XLA家系成员的外周血标本,应用PCR扩增和直接测序方法对3例XLA患者进行Bruton酪氨酸激酶(BTK)基因测序,分析BTK基因外显子区和剪切区DNA序列改变情况,采用PROVEN、PolyPhen-2和ClustalO软件对新发现的错义突变进行功能预测.在确定每个家系基因型后,对家系2和家系3中的2个高危胎儿抽取绒毛进行产前诊断.结果家系1中,先证者及其母亲携带BTK基因c.1117C ＞A(p.L373I)错义突变,采用功能预测软件分析为致病突变的可能性大;家系2中,先证者及其母亲携带BTK基因c.126T＞G(p.Y42X)无义突变;家系3中,先证者及其母亲携带c.1679delC(p.P560fsX10)缺失突变.3个XLA家系发现的3种BTK基因突变为新突变,100名健康个体BTK基因相应区域测序,未发现有上述同样序列改变.对明确致病突变的家系2和家系3胎儿行孕早期产前诊断,家系2胎儿为p.Y42X女性杂合突变携带者,家系3胎儿为男性未携带突变基因者,2对夫妇均选择继续妊娠,胎儿娩出后随访结果与产前诊断结果一致.结论发现3个BTK基因新变异,BTK基因p.Y42X和p.P560fsX10突变是家系2和家系3患者的致病原因,BTK基因p.L373I突变可能是家系1患者致病的主要原因,但需要功能验证.对于有XLA生育史的夫妇再次生育时,应用基因测序技术行产前BTK基因突变分析可以有效地预防患儿出生.
목적 대X-련쇄무병충구단백혈증(XLA)가계진행치병기인돌변분석급산전진단.방법 수집2011년1월지2012년6월재정주대학제일부속의원취진적3개XLA가계성원적외주혈표본,응용PCR확증화직접측서방법대3례XLA환자진행Bruton락안산격매(BTK)기인측서,분석BTK기인외현자구화전절구DNA서렬개변정황,채용PROVEN、PolyPhen-2화ClustalO연건대신발현적착의돌변진행공능예측.재학정매개가계기인형후,대가계2화가계3중적2개고위태인추취융모진행산전진단.결과 가계1중,선증자급기모친휴대BTK기인c.1117C ＞A(p.L373I)착의돌변,채용공능예측연건분석위치병돌변적가능성대;가계2중,선증자급기모친휴대BTK기인c.126T＞G(p.Y42X)무의돌변;가계3중,선증자급기모친휴대c.1679delC(p.P560fsX10)결실돌변.3개XLA가계발현적3충BTK기인돌변위신돌변,100명건강개체BTK기인상응구역측서,미발현유상술동양서렬개변.대명학치병돌변적가계2화가계3태인행잉조기산전진단,가계2태인위p.Y42X녀성잡합돌변휴대자,가계3태인위남성미휴대돌변기인자,2대부부균선택계속임신,태인면출후수방결과여산전진단결과일치.결론 발현3개BTK기인신변이,BTK기인p.Y42X화p.P560fsX10돌변시가계2화가계3환자적치병원인,BTK기인p.L373I돌변가능시가계1환자치병적주요원인,단수요공능험증.대우유XLA생육사적부부재차생육시,응용기인측서기술행산전BTK기인돌변분석가이유효지예방환인출생.
Objective To evaluate the genetic diagnostic feasibility of Bruton's tyrosine kinase (BTK) gene in three families with X-linked agammagobulinemia (XLA) birth history,mutation analysis and prenatal genetic diagnosis of BTK gene for two families with XLA.Methods Polymerase chain reaction (PCR) was applied to amplify the regions of exon and exon-intron boundaries of BTK gene in 3 unrelated patients of XLA and their mothers from January 2011 to June 2012.The PCR products were further analyzed by direct sequencing.Prenatal genetic diagnosis was performed by chorionic villus sampling after genotyping of mothers of probands.Results Three novel mutations of BTK gene were identified in 3 pedigrees of XLA.A missense mutation c.1117C ＞ A(p.L373I)were detected in pedigree 1.The mutation was possible damage by predicting in sillico.A nonsense mutation c.126T ＞ G(p.Y42X)was found in pedigree 2.A single base deletion mutation c.1679delC(p.P560fsX10)was found in pedigree 3.The three mutations,p.L373I,p.Y42X and p.P560fsX10 were novel.The three novel mutations were absent in the 100 normal controls.The male fetus in pedigree 3 was free of mutations identical to the proband and the female fetus in pedigree 2 was a carrier.The two families continued the pregnancies and the infants showed no symptom of XLA after one year old.Conclusions Three novel mutations were identified.The mutations of p.Y42X and p.P560fsX10 in BTK gene may be the major causes of pedigrees 2 and 3 with XLA.The mutation p.L373I of BTK gene is possibly the cause of pedigree 1 with XLA,but functional verification is needed.For pedigree of XLA,direct sequencing of BTK gene is available for providing genetic counseling,prenatal diagnosis.