目的探讨婴儿型Sandhoff病临床及基因突变特点。方法回顾性分析1例婴儿型Sandhoff病患儿的临床资料以及基因检测结果。结果高通量测序结合Sanger测序验证结果显示患儿携带HEXB基因c.1540-1541del(p.Trp514fs)和c.1404delT(p.Pro468fs),...目的探讨婴儿型Sandhoff病临床及基因突变特点。方法回顾性分析1例婴儿型Sandhoff病患儿的临床资料以及基因检测结果。结果高通量测序结合Sanger测序验证结果显示患儿携带HEXB基因c.1540-1541del(p.Trp514fs)和c.1404delT(p.Pro468fs),依据美国医学遗传学和基因组学协会(American College of Medical Genetics and Genomics,ACMG)指南,判定该变异为致病性变异。结论Sandhoff disease(SD)是由HEXB基因突变引起β-氨基己糖苷酶活性不足,从而导致GM2神经节苷脂在神经系统大量积累,是一种罕见的遗传性溶酶体病,目前缺乏有效的治疗方法。展开更多
Background Sandhoff disease(SD)i s an autosomal recessive lysosomal disease with clinical manifestations such as epilepsy,psychomotor retardation and developmental delay.However,infantile SD with onset of infantile ep...Background Sandhoff disease(SD)i s an autosomal recessive lysosomal disease with clinical manifestations such as epilepsy,psychomotor retardation and developmental delay.However,infantile SD with onset of infantile epilepsy spasm syndrome(IESS)is extremely rare.Case presentation The case presented here was a 22-month-old boy,who presented with IESS and psychomotor retardation/regression at 6 months of age.The patient showed progressive aggravation of seizures and excessive startle responses.The whole exome sequencing data,which initially revealed negative results,were reanalyzed and indicated a homozygous mutation at the c.1613+4del splice site of the HEXB gene.The activities ofβ-hexosaminidase A and total hexosaminidase were significantly decreased.The fundus examination showed cherry red spots at the macula.Conclusions IESS can be an epileptic phenotype of infantile SD.Clinical phenotypes should be adequately collected in genetic testing.In the case of negative sequencing results,gene variant reanalysis can be performed when the patients show clinically suspicious indications.展开更多
GM2 gangliosidoses are a group of autosomal-recessive lysosomal storage disorde rs.These diseases result from a deficiency of lysosomal enzymeβ-hexosaminidase A(HexA),which is responsible for GM2 ganglioside degradat...GM2 gangliosidoses are a group of autosomal-recessive lysosomal storage disorde rs.These diseases result from a deficiency of lysosomal enzymeβ-hexosaminidase A(HexA),which is responsible for GM2 ganglioside degradation.HexA deficiency causes the accumulation of GM2-gangliosides mainly in the nervous system cells,leading to severe progressive neurodegeneration and neuroinflammation.To date,there is no treatment for these diseases.Cell-mediated gene therapy is considered a promising treatment for GM2 gangliosidoses.This study aimed to evaluate the ability of genetically modified mesenchymal stem cells(MSCs-HEXA-HEXB)to restore HexA deficiency in Tay-Sachs disease patient cells,as well as to analyze the functionality and biodistribution of MSCs in vivo.The effectiveness of HexA deficiency cross-correction was shown in mutant MSCs upon intera ction with MSCs-HEXA-HEXB.The results also showed that the MSCs-HEXA-HEXB express the functionally active HexA enzyme,detectable in vivo,and intravenous injection of the cells does not cause an immune response in animals.These data suggest that genetically modified mesenchymal stem cells have the potentials to treat GM2 gangliosidoses.展开更多
Tay-Sachs disease and Sandhoff disease are severe hereditary neurodegenerative disorders caused by a deficiency ofβ-hexosaminidase A(HexA)enzyme,which results in the accumulation of GM2 gangliosides in the nervous sy...Tay-Sachs disease and Sandhoff disease are severe hereditary neurodegenerative disorders caused by a deficiency ofβ-hexosaminidase A(HexA)enzyme,which results in the accumulation of GM2 gangliosides in the nervous system cells.In this work,we analyzed the efficacy and safety of cell-mediated gene therapy for Sandhoff disease and Sandhoff disease using a bicistronic lentiviral vector encoding cDNA of HexAα-andβ-subunit genes separated by the nucleotide sequence of a P2A peptide(HEXA-HEXB).The functionality of the bicistronic construct containing the HEXA-HEXB genetic cassette was analyzed in a culture of HEK293T cells and human umbilical cord blood mononuclear cells(hUCBMCs).Our results showed that the enzymatic activity of HexA in the conditioned medium harvested from genetically modified HEK293T-HEXA-HEXB and hUCBMCs-HEXA-HEXB was increased by 23 and 8 times,respectively,compared with the conditioned medium of native cells.Western blot analysis showed that hUCBMCs-HEXA-HEXB secreted both completely separated HEXA and HEXB proteins,and an uncleaved protein containing HEXA+HEXB linked by the P2A peptide.Intravenous injection of genetically modified hUCBMCs-HEXA-HEXB to laboratory Wistar rats was carried out,and the HexA enzymatic activity in the blood plasma of experimental animals,as well as the number of live cells of immune system organs(spleen,thymus,bone marrow,lymph nodes)were determined.A significant increase in the enzymatic activity of HexA in the blood plasma of laboratory rats on days 6 and 9(by 2.5 and 3 times,respectively)after the administration of hUCBMCsHEXA-HEXB was shown.At the same time,the number of live cells in the studied organs remained unchanged.Thus,the functionality of the bicistronic genetic construct encoding cDNA of the HEXA and HEXB genes separated by the nucleotide sequence of the P2A peptide was shown in vitro and in vivo.We hypothesize that due to the natural ability of hUCBMCs to overcome biological barriers,such a strategy can restore the activity of the missing enzyme in the central nervous system of patients with GM2 gangliosidoses.Based on the obtained data,it can be concluded that intravenous administration of hUCBMCs with HexA overexpression is a promising method of the therapy for GM2 gangliosidoses.The animal protocol was approved by the Animal Ethics Committee of the Kazan Federal University(No.23)on June 30,2020.展开更多
文摘目的探讨婴儿型Sandhoff病临床及基因突变特点。方法回顾性分析1例婴儿型Sandhoff病患儿的临床资料以及基因检测结果。结果高通量测序结合Sanger测序验证结果显示患儿携带HEXB基因c.1540-1541del(p.Trp514fs)和c.1404delT(p.Pro468fs),依据美国医学遗传学和基因组学协会(American College of Medical Genetics and Genomics,ACMG)指南,判定该变异为致病性变异。结论Sandhoff disease(SD)是由HEXB基因突变引起β-氨基己糖苷酶活性不足,从而导致GM2神经节苷脂在神经系统大量积累,是一种罕见的遗传性溶酶体病,目前缺乏有效的治疗方法。
基金funded by the Capital’s Funds for Health Improvement and Research(No.2022-1-5081).
文摘Background Sandhoff disease(SD)i s an autosomal recessive lysosomal disease with clinical manifestations such as epilepsy,psychomotor retardation and developmental delay.However,infantile SD with onset of infantile epilepsy spasm syndrome(IESS)is extremely rare.Case presentation The case presented here was a 22-month-old boy,who presented with IESS and psychomotor retardation/regression at 6 months of age.The patient showed progressive aggravation of seizures and excessive startle responses.The whole exome sequencing data,which initially revealed negative results,were reanalyzed and indicated a homozygous mutation at the c.1613+4del splice site of the HEXB gene.The activities ofβ-hexosaminidase A and total hexosaminidase were significantly decreased.The fundus examination showed cherry red spots at the macula.Conclusions IESS can be an epileptic phenotype of infantile SD.Clinical phenotypes should be adequately collected in genetic testing.In the case of negative sequencing results,gene variant reanalysis can be performed when the patients show clinically suspicious indications.
基金supported by the subsidy allocated to Kazan Federal University for the state assignment#0671-2020-0058 in the sphere of scientific activities(to AAR)the Kazan Federal University Strategic Academic Leadership Program(PRIORITY-2030)。
文摘GM2 gangliosidoses are a group of autosomal-recessive lysosomal storage disorde rs.These diseases result from a deficiency of lysosomal enzymeβ-hexosaminidase A(HexA),which is responsible for GM2 ganglioside degradation.HexA deficiency causes the accumulation of GM2-gangliosides mainly in the nervous system cells,leading to severe progressive neurodegeneration and neuroinflammation.To date,there is no treatment for these diseases.Cell-mediated gene therapy is considered a promising treatment for GM2 gangliosidoses.This study aimed to evaluate the ability of genetically modified mesenchymal stem cells(MSCs-HEXA-HEXB)to restore HexA deficiency in Tay-Sachs disease patient cells,as well as to analyze the functionality and biodistribution of MSCs in vivo.The effectiveness of HexA deficiency cross-correction was shown in mutant MSCs upon intera ction with MSCs-HEXA-HEXB.The results also showed that the MSCs-HEXA-HEXB express the functionally active HexA enzyme,detectable in vivo,and intravenous injection of the cells does not cause an immune response in animals.These data suggest that genetically modified mesenchymal stem cells have the potentials to treat GM2 gangliosidoses.
基金funded by the subsidy allocated to Kazan Federal University for the state assignment#0671-2020-0058 in the sphere of scientific activities。
文摘Tay-Sachs disease and Sandhoff disease are severe hereditary neurodegenerative disorders caused by a deficiency ofβ-hexosaminidase A(HexA)enzyme,which results in the accumulation of GM2 gangliosides in the nervous system cells.In this work,we analyzed the efficacy and safety of cell-mediated gene therapy for Sandhoff disease and Sandhoff disease using a bicistronic lentiviral vector encoding cDNA of HexAα-andβ-subunit genes separated by the nucleotide sequence of a P2A peptide(HEXA-HEXB).The functionality of the bicistronic construct containing the HEXA-HEXB genetic cassette was analyzed in a culture of HEK293T cells and human umbilical cord blood mononuclear cells(hUCBMCs).Our results showed that the enzymatic activity of HexA in the conditioned medium harvested from genetically modified HEK293T-HEXA-HEXB and hUCBMCs-HEXA-HEXB was increased by 23 and 8 times,respectively,compared with the conditioned medium of native cells.Western blot analysis showed that hUCBMCs-HEXA-HEXB secreted both completely separated HEXA and HEXB proteins,and an uncleaved protein containing HEXA+HEXB linked by the P2A peptide.Intravenous injection of genetically modified hUCBMCs-HEXA-HEXB to laboratory Wistar rats was carried out,and the HexA enzymatic activity in the blood plasma of experimental animals,as well as the number of live cells of immune system organs(spleen,thymus,bone marrow,lymph nodes)were determined.A significant increase in the enzymatic activity of HexA in the blood plasma of laboratory rats on days 6 and 9(by 2.5 and 3 times,respectively)after the administration of hUCBMCsHEXA-HEXB was shown.At the same time,the number of live cells in the studied organs remained unchanged.Thus,the functionality of the bicistronic genetic construct encoding cDNA of the HEXA and HEXB genes separated by the nucleotide sequence of the P2A peptide was shown in vitro and in vivo.We hypothesize that due to the natural ability of hUCBMCs to overcome biological barriers,such a strategy can restore the activity of the missing enzyme in the central nervous system of patients with GM2 gangliosidoses.Based on the obtained data,it can be concluded that intravenous administration of hUCBMCs with HexA overexpression is a promising method of the therapy for GM2 gangliosidoses.The animal protocol was approved by the Animal Ethics Committee of the Kazan Federal University(No.23)on June 30,2020.
