Idiopathic basal ganglia calcification associated with new MYORG mutation site:A case report

BACKGROUND Idiopathic basal ganglia calcification(IBGC)is a neurodegenerative disease characterized by symmetrical calcification of basal ganglia and other brain region,also known as Fahr’s disease.It can be sporadic or familial,and there is no definite etiology at present.With the development of neuroimaging,the number of reports of IBGC has increased in recent years.However,due to its hidden onset,diverse clinical manifestations,and low incidence,it is likely to be misdiagnosed or ignored by potential patients and their family.CASE SUMMARY We report a case of a 61-year-old man who presented with symptoms of dysphagia and alalia.His computed tomography scan of the brain revealed bilateral symmetric calcifications of basal ganglia,cerebellum,thalamus,and periventricular area.The genetic test showed a new mutation sites of MYORG,c.1438T>G mutation and c.1271_1272 TGGTGCGC insertion mutation.He was finally diagnosed with IBGC.CONCLUSION It is important to detect MYORG mutation when IBGC is suspected,especially in those without an obvious family history,for better understanding of the underlying mechanism and identifying potential treatments.

Identification of a Novel Homozygous Splice-Site Mutation in SCARB2 that Causes Progressive Myoclonus Epilepsy with or without Renal Failure

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.