目的研究一例疑是视网膜变性的患儿,进行基因检测并作出明确的基因诊断。方法常规检查患儿和家属的眼睛,特别是视网膜的情况。收集患者及家庭成员的外周静脉血液,提取基因组DNA。通过目标区域外显子组序列捕获联合新一代测序(简称目标...目的研究一例疑是视网膜变性的患儿,进行基因检测并作出明确的基因诊断。方法常规检查患儿和家属的眼睛,特别是视网膜的情况。收集患者及家庭成员的外周静脉血液,提取基因组DNA。通过目标区域外显子组序列捕获联合新一代测序(简称目标区域测序),利用生物信息学分析筛选出一系列可能的突变,再通过Sanger测序和共分离研究进行验证,从而确定先证者的致病突变。最后,通过PCR和Sanger测序检测突变基因。结果患儿视力障碍严重,眼底检查所见符合视网膜变性。其他人眼睛正常。基因诊断结果表明,先证者携带CRB1基因的复合杂合性致病突变(c.3521G>C和c.1141_1142 ins TGGCT)。这两个突变分别来源于父亲(c.3521G>C,p.C1174S)和母亲(c.1141_1142ins TGGCT),为隐性遗传。患儿的弟弟(新生儿)只有一个c.1141_1142ins TGGCT突变,表明他不会发病。建议新生儿长大后在生育前要进行遗传检查和咨询。结论目标区域测序的基因诊断方法是检测视网膜变性疾病突变基因的强大工具,有利于对患者做出早期、明确、分子水平的诊断,在特定疾病的理解、预防和预后判定方面能发挥重要作用。同时为其尚无法做临床检查和诊断的新生儿弟弟进行了基因诊断,通过预测,排除了发病的可能。展开更多
Background:The loss of cell polarity plays a key part in retinal dystrophies such as retinitis pigmentosa(RP)and Leber congenital amaurosis(LCA),resulting in photoreceptor(PR)degeneration and vision loss.Despite not k...Background:The loss of cell polarity plays a key part in retinal dystrophies such as retinitis pigmentosa(RP)and Leber congenital amaurosis(LCA),resulting in photoreceptor(PR)degeneration and vision loss.Despite not knowing the direct genotype-to-phenotype correlation,many disease-causing mutations in the polarity determinant Crumbs(Crb1),have been identified.Indeed,the loss of Crb1 in mice was shown to cause PR death,due to the loss of adhesions between PR and Müller cells at the apical surface of the retina.Unfortunately,although the role of Crb1 in neuron polarity and survival is well established,little is known about how its intracellular trafficking is regulated.With future treatments for retinal degenerative diseases in mind,the goal of this project is to understand the mechanism by which Crb1 is regulated and how it maintains retinal integrity.Previous work in our laboratory showed that Numb,an endocytic adaptor protein,is an important regulator of protein trafficking in retinal cells.We therefore hypothesized that Numb might function as regulator of Crb1 in Müller glia.Methods:To study Numb function in Müller cells,we generated a conditional knockout(cKO)mouse line to inactivate Numb specifically in Müller cells by crossing a Glast-CreERT2 mouse line with a Numb-floxed line.At 30 days,mice were administered tamoxifen to trigger inactivation of Numb and retinas were then collected at time points varying from 2 weeks to 17 months for analysis.Firstly,we studied the retinal morphology and outer limiting membrane integrity by histology and immunohistochemistry.Using electron microscopy(EM),adhesions between Müller glia and photoreceptors were analysed and retinal function was assayed in live mice by electroretinography(ERG).To detect protein expression levels,protein extracts were prepared from cKO and control retinas for immunoblotting.To test for the presence of a biochemical interaction,Hek-293 cells were transfected with Numb and Crb1 vectors,and protein extracts were processed for co-immunoprecipita展开更多
文摘目的研究一例疑是视网膜变性的患儿,进行基因检测并作出明确的基因诊断。方法常规检查患儿和家属的眼睛,特别是视网膜的情况。收集患者及家庭成员的外周静脉血液,提取基因组DNA。通过目标区域外显子组序列捕获联合新一代测序(简称目标区域测序),利用生物信息学分析筛选出一系列可能的突变,再通过Sanger测序和共分离研究进行验证,从而确定先证者的致病突变。最后,通过PCR和Sanger测序检测突变基因。结果患儿视力障碍严重,眼底检查所见符合视网膜变性。其他人眼睛正常。基因诊断结果表明,先证者携带CRB1基因的复合杂合性致病突变(c.3521G>C和c.1141_1142 ins TGGCT)。这两个突变分别来源于父亲(c.3521G>C,p.C1174S)和母亲(c.1141_1142ins TGGCT),为隐性遗传。患儿的弟弟(新生儿)只有一个c.1141_1142ins TGGCT突变,表明他不会发病。建议新生儿长大后在生育前要进行遗传检查和咨询。结论目标区域测序的基因诊断方法是检测视网膜变性疾病突变基因的强大工具,有利于对患者做出早期、明确、分子水平的诊断,在特定疾病的理解、预防和预后判定方面能发挥重要作用。同时为其尚无法做临床检查和诊断的新生儿弟弟进行了基因诊断,通过预测,排除了发病的可能。
文摘Background:The loss of cell polarity plays a key part in retinal dystrophies such as retinitis pigmentosa(RP)and Leber congenital amaurosis(LCA),resulting in photoreceptor(PR)degeneration and vision loss.Despite not knowing the direct genotype-to-phenotype correlation,many disease-causing mutations in the polarity determinant Crumbs(Crb1),have been identified.Indeed,the loss of Crb1 in mice was shown to cause PR death,due to the loss of adhesions between PR and Müller cells at the apical surface of the retina.Unfortunately,although the role of Crb1 in neuron polarity and survival is well established,little is known about how its intracellular trafficking is regulated.With future treatments for retinal degenerative diseases in mind,the goal of this project is to understand the mechanism by which Crb1 is regulated and how it maintains retinal integrity.Previous work in our laboratory showed that Numb,an endocytic adaptor protein,is an important regulator of protein trafficking in retinal cells.We therefore hypothesized that Numb might function as regulator of Crb1 in Müller glia.Methods:To study Numb function in Müller cells,we generated a conditional knockout(cKO)mouse line to inactivate Numb specifically in Müller cells by crossing a Glast-CreERT2 mouse line with a Numb-floxed line.At 30 days,mice were administered tamoxifen to trigger inactivation of Numb and retinas were then collected at time points varying from 2 weeks to 17 months for analysis.Firstly,we studied the retinal morphology and outer limiting membrane integrity by histology and immunohistochemistry.Using electron microscopy(EM),adhesions between Müller glia and photoreceptors were analysed and retinal function was assayed in live mice by electroretinography(ERG).To detect protein expression levels,protein extracts were prepared from cKO and control retinas for immunoblotting.To test for the presence of a biochemical interaction,Hek-293 cells were transfected with Numb and Crb1 vectors,and protein extracts were processed for co-immunoprecipita
