中华实验眼科杂志
中華實驗眼科雜誌
중화실험안과잡지
CHINESE JOURNAL OF EXPERIMENTAL OPHTHALMOLOGY
2015年
8期
722-726
,共5页
张晓慧%刘卫华%董冰%陈洁琼%李杨
張曉慧%劉衛華%董冰%陳潔瓊%李楊
장효혜%류위화%동빙%진길경%리양
先天性白内障%白内障/遗传学%DNA突变分析%晶状体核/病理%家系谱%γ-晶状体蛋白/遗传%基因突变%中国人
先天性白內障%白內障/遺傳學%DNA突變分析%晶狀體覈/病理%傢繫譜%γ-晶狀體蛋白/遺傳%基因突變%中國人
선천성백내장%백내장/유전학%DNA돌변분석%정상체핵/병리%가계보%γ-정상체단백/유전%기인돌변%중국인
Cataract/congenital%Cataract/genetics%DNA mutational analysis%Lens nucleus,crystalline/pathology%Pedigree%gamma-Crystallin/genetics%Mutations%Chinese
背景 先天性白内障是儿童致盲的主要原因之一,约1/3的先天性白内障由遗传因素引起,多为常染色体显性遗传,目前确定至少26个基因为常染色体显性遗传先天性白内障(ADCC)的致病基因,发现的致病基因突变已超过100种.目的 明确一ADCC家系的致病基因突变.方法 对2011年1月在北京同仁医院就诊的一来自河北的汉族ADCC家系进行分析,在获得受检者知情同意后,对所有家系成员进行详细的眼科检查并采集外周静脉血各5 ml,提取全基因组DNA.在已知的17个ADCC致病基因周围选取21个荧光标记的微卫星,经多重PCR扩增后进行连锁分析,两点法计算LOD值.对候选基因进行DNA直接测序分析,用ProtScale软件对基因突变前后蛋白局部的疏水性进行分析.用限制性片段长度多态性(RFLP)方法对所有家系成员及100个正常对照者进行基因突变共分离分析.结果 该家系共4代20名成员,其中患者9例,连续4代均有患者发病,符合常染色体显性遗传特征.临床检查证实9例患者均为双眼晶状体核性混浊.连锁分析发现微卫星D2S325和D2S2358与该家系中所有患者均连锁,重组分数(θ)为0时D2S325获得最大LOD值,为4.68.对位于D2S325附近的CRYGC和CR YGD基因进行DNA直接测序,发现CRYGD基因cDNA第127位一已知错义突变(c.T127C),导致编码蛋白第43位色氨酸变为精氨酸(p.W43R).ProtScale软件预测突变后的CRYGD蛋白第43位及其周围氨基酸疏水性明显增加.该突变与家系内所有患者表型共分离,家系中表型正常的成员及100名正常对照者均未发现此突变.结论 CRYGD基因c.T127C突变是该ADCC家系的致病基因突变,蛋白局部疏水性增加造成的空间结构异常可能是引起该ADCC家系发病的主要原因.
揹景 先天性白內障是兒童緻盲的主要原因之一,約1/3的先天性白內障由遺傳因素引起,多為常染色體顯性遺傳,目前確定至少26箇基因為常染色體顯性遺傳先天性白內障(ADCC)的緻病基因,髮現的緻病基因突變已超過100種.目的 明確一ADCC傢繫的緻病基因突變.方法 對2011年1月在北京同仁醫院就診的一來自河北的漢族ADCC傢繫進行分析,在穫得受檢者知情同意後,對所有傢繫成員進行詳細的眼科檢查併採集外週靜脈血各5 ml,提取全基因組DNA.在已知的17箇ADCC緻病基因週圍選取21箇熒光標記的微衛星,經多重PCR擴增後進行連鎖分析,兩點法計算LOD值.對候選基因進行DNA直接測序分析,用ProtScale軟件對基因突變前後蛋白跼部的疏水性進行分析.用限製性片段長度多態性(RFLP)方法對所有傢繫成員及100箇正常對照者進行基因突變共分離分析.結果 該傢繫共4代20名成員,其中患者9例,連續4代均有患者髮病,符閤常染色體顯性遺傳特徵.臨床檢查證實9例患者均為雙眼晶狀體覈性混濁.連鎖分析髮現微衛星D2S325和D2S2358與該傢繫中所有患者均連鎖,重組分數(θ)為0時D2S325穫得最大LOD值,為4.68.對位于D2S325附近的CRYGC和CR YGD基因進行DNA直接測序,髮現CRYGD基因cDNA第127位一已知錯義突變(c.T127C),導緻編碼蛋白第43位色氨痠變為精氨痠(p.W43R).ProtScale軟件預測突變後的CRYGD蛋白第43位及其週圍氨基痠疏水性明顯增加.該突變與傢繫內所有患者錶型共分離,傢繫中錶型正常的成員及100名正常對照者均未髮現此突變.結論 CRYGD基因c.T127C突變是該ADCC傢繫的緻病基因突變,蛋白跼部疏水性增加造成的空間結構異常可能是引起該ADCC傢繫髮病的主要原因.
배경 선천성백내장시인동치맹적주요원인지일,약1/3적선천성백내장유유전인소인기,다위상염색체현성유전,목전학정지소26개기인위상염색체현성유전선천성백내장(ADCC)적치병기인,발현적치병기인돌변이초과100충.목적 명학일ADCC가계적치병기인돌변.방법 대2011년1월재북경동인의원취진적일래자하북적한족ADCC가계진행분석,재획득수검자지정동의후,대소유가계성원진행상세적안과검사병채집외주정맥혈각5 ml,제취전기인조DNA.재이지적17개ADCC치병기인주위선취21개형광표기적미위성,경다중PCR확증후진행련쇄분석,량점법계산LOD치.대후선기인진행DNA직접측서분석,용ProtScale연건대기인돌변전후단백국부적소수성진행분석.용한제성편단장도다태성(RFLP)방법대소유가계성원급100개정상대조자진행기인돌변공분리분석.결과 해가계공4대20명성원,기중환자9례,련속4대균유환자발병,부합상염색체현성유전특정.림상검사증실9례환자균위쌍안정상체핵성혼탁.련쇄분석발현미위성D2S325화D2S2358여해가계중소유환자균련쇄,중조분수(θ)위0시D2S325획득최대LOD치,위4.68.대위우D2S325부근적CRYGC화CR YGD기인진행DNA직접측서,발현CRYGD기인cDNA제127위일이지착의돌변(c.T127C),도치편마단백제43위색안산변위정안산(p.W43R).ProtScale연건예측돌변후적CRYGD단백제43위급기주위안기산소수성명현증가.해돌변여가계내소유환자표형공분리,가계중표형정상적성원급100명정상대조자균미발현차돌변.결론 CRYGD기인c.T127C돌변시해ADCC가계적치병기인돌변,단백국부소수성증가조성적공간결구이상가능시인기해ADCC가계발병적주요원인.
Background Congenital cataract is a major cause for blindness of childhood.Genetic gene mutation accounts for almost 1/3 of congenital cataract patients.The most common inheritance type is autosomal dominant congenital cataract (ADCC).Over 100 mutations in 26 genes have been found to be associated with ADCC.Objective This study was to identify the disease-causing gene mutation in a family with ADCC.Methods This study was approved by Ethic Committee of Beijing Tongren Hospital and followed Declaration of Helsinki.A northern Chinese family with autosomal dominant congenital nuclear cataract was entrolled in Beijing Tongren Hospital in January 2011.Ocular examinations were performed and periphery blood specimens were collected from each family member under the informed consent.Genomic DNA was extracted.Twenty-one microsatellite markers around 17 ADCC genes were selected for linkage analysis,and two-point LOD score was calculated.CRYGC gene and CRYGD gene were amplified and screened for mutations using direct sequencing.ProtScale software was used to analyze the changes of hydrophobicity of the mutated protein.Co-segregation of the observed change with the disease phenotype was further detected by restriction fragment length polymorphism (RFLP).Results This family included 20 members of 4 generations,and 9 patients were examined in serial 4 passages,which conformed to autosomal dominant inheritance pattern.Clinical examination revealed binocular congenital nuclear cataract in the 9 patients.Maximum two-point LOD score was 4.68 at marker D2S325 (θ=0).A known T→C change at position 127 of cDNA sequence was found by mutations screening of CRYGD gene.ProtScale programs showed an obvious increase of the local hydrophobicity in the mutant protein.RFLP results indicated that this missense mutation co-segregated with affected members of the family,but was absent in unaffected members and 100 unrelated controls.Conclusions c.T127C mutation of CRYGD gene appears to be the molecular pathogenesis of this ADCC family.Aberrant structure of mutant CRYGD protein caused by hydrophobicity change may lead to opacification of lens.
