Background： Progressive myoclonus epilepsies （PMEs） conaprise a group of rare genetic disorders characterized by action rnyoclonus, epileptic seizures, and ataxia with progressive neurologic decline. Due to clinica...Background： Progressive myoclonus epilepsies （PMEs） conaprise a group of rare genetic disorders characterized by action rnyoclonus, epileptic seizures, and ataxia with progressive neurologic decline. Due to clinical and genetic heterogeneity of PMEs, it is difficult to decide which genes are affected. The aim of this study was to report an action myoclonus with or without renal failure syndrome （EPM4） fhmily and summarize the clinical and genetic characteristics of all reported EPM4 patients. Meihods： In the present study, targeted next-generation sequencing （NGS） was applied to screen causative genes in a Chinese PME family. The candidaie variant was further confirmed by cosegregation analysis and further functional analysis, including the reverse transcription polymerase chain reaction and Western blot of the proband＇s muscle. Moreovel, literature data on the clinical and mutational features of all reported EPM4 patients were reviewed. Results： The gene analysis revealed a novel homozygous splicing mutation （c.995-1G〉A） of the SCARB2 gene in two brothers. Further functional analysis revealed that this mutation led to loss function of the SCARB2 protein. The classification of the candidate variant, according to the American College of Medical Genetics and Genomics standards and guidelines and functional analysis, was pathogenic. Therefore, these two brothers were finally diagnostically confirmed as EPM4. Conclusions： These present results suggest the potential for targeted NGS to conduct a more rapid and precise diagnosis for PME patients. A literature review revealed that mutations in the different functional domains of SCARB2 appear to be associated with the phenotype of EPM4.展开更多
基金This work was supported by the grants from the National Natural Science Foundation of China （No. U1505222, No, 81322017, No. 81500980, and No. 81571100） and the National Key Clinical Specialty Discipline Construction Program and Key Clinical Specialty Discipline Construction Program of Fujian.
文摘Background： Progressive myoclonus epilepsies （PMEs） conaprise a group of rare genetic disorders characterized by action rnyoclonus, epileptic seizures, and ataxia with progressive neurologic decline. Due to clinical and genetic heterogeneity of PMEs, it is difficult to decide which genes are affected. The aim of this study was to report an action myoclonus with or without renal failure syndrome （EPM4） fhmily and summarize the clinical and genetic characteristics of all reported EPM4 patients. Meihods： In the present study, targeted next-generation sequencing （NGS） was applied to screen causative genes in a Chinese PME family. The candidaie variant was further confirmed by cosegregation analysis and further functional analysis, including the reverse transcription polymerase chain reaction and Western blot of the proband＇s muscle. Moreovel, literature data on the clinical and mutational features of all reported EPM4 patients were reviewed. Results： The gene analysis revealed a novel homozygous splicing mutation （c.995-1G〉A） of the SCARB2 gene in two brothers. Further functional analysis revealed that this mutation led to loss function of the SCARB2 protein. The classification of the candidate variant, according to the American College of Medical Genetics and Genomics standards and guidelines and functional analysis, was pathogenic. Therefore, these two brothers were finally diagnostically confirmed as EPM4. Conclusions： These present results suggest the potential for targeted NGS to conduct a more rapid and precise diagnosis for PME patients. A literature review revealed that mutations in the different functional domains of SCARB2 appear to be associated with the phenotype of EPM4.
