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.

Idiopathic Basal Ganglia Calcification Presented with Progressive Supranuclear Palsy-like Features

Fahr＇s disease, or idiopathic basal ganglia calcification （IBGC）, is a rare neurological syndrome characterized by abnormal calcified deposits located mostly in bilateral basal ganglia and dentate nucleus, and also in cerebral cortex, thalamus, hippocampus, cerebellar, and subcortical white matter. Clinically, it presents various symptoms, including parkinsonism （presented in 57% of the patientsL chorea （ 19%）, tremors （8%）, dystonia （8%）, athetosis （5%）~ and orofacial dyskinesia （3%）.

A Novel SLC2OA2 Mutation Associated with Familial Idiopathic Basal Ganglia Calcification and Analysis of the Genotype-Phenotype Association in Chinese Patients

Background： Idiopathic basal ganglia calcification （IBGC） is a genetic disorder characterized by bilateral basal ganglia calcification and neural degeneration. In this study, we reported a new SLC2OA2 mutation of IBGC and reviewed relevant literature to explore the association between phenotypes and genotypes in Chinese IBGC patients. Methods： Clinical information of the proband and her relatives were collected comprehensively. Blood samples of both the patient and her father were obtained, and genetic screening related to IBGC was performed using second generation sequencing with their consent. Findings were confirmed by Sanger sequencing. Polyphen-2 was used to predict the potential association between mutations and disease. Then, we retrieved literatures of Chinese IBGC patients and explored the association between phenotype and genotype. Results： A novel mutation was identified through genetic testing, and it is suggested to be a damage mutation predicted by Polyphen-2. Through literature review, we tbund that SLC2OA2 mutation is the most common cause for IBGC in China. Its hot spot regions are mainly on the 1^st and 8th exons; the second common one is PDGFB where the hot spot covered a length of 220-230 bp localized on the 2^nd exon; moreover, Chinese IBGC patients featured early-onset, more severe movement disorder and relatively mild cognitive impairment compared with those in other countries. Conclusions： There is significant heterogeneity both in phenotype and genotype in Chinese IBGC patients. Further research of pathogenic mechanism of IBGC is required to eventually develop precise treatment for individuals who suffered this disease.