OBJECTIVE: To analyze the clinical characteristics and genotypic changes of six children with RARS2 gene variants. METHODS: The clinical data of 6 children with RARS2 gene variants diagnosed at the Third Affiliated Hospital of Zhengzhou University from January 2017 to August 2024 were collected. Genetic variants were detected using trio-whole exome sequencing. Genomic DNA was extracted from samples and subjected to high-throughput sequencing. Variants were detected and analyzed using relevant databases and software. Pathogenic variants were validated by Sanger sequencing. The protein structure encoded by a previously unreported variant was predicted using a SWISS-MODEL online server. This study was approved by the Medical Ethics Committee of the Third Affiliated Hospital of Zhengzhou University (Ethics No.: 2024-373-01). RESULTS: Among the six children, four were males and two were females, with the most recent follow-up age ranging from 1-year-and-1-month to 7 years old. The age of onset was under 1 year in all cases. All six children exhibited seizures, including infantile spasms in three, spasms and tonic spasms in one, and focal seizures in two. One child became seizure-free for 4 ~ 5 years following Valproic acid combined with topiramate and adrenocorticotropic hormone (ACTH) pulse therapy, but subsequently experienced a relapse. Another child has remained seizure-free for nearly one year with oral sodium valproate, levetiracetam, and a "cocktail" therapy. Seizures were not controlled in the remaining four children. Pontocerebellar hypoplasia was observed on neuroimaging in two children. All six patients exhibited severe psychomotor retardation. A total of 10 RARS2 gene variants were identified, three of which were previously unreported. CONCLUSION The predominant clinical features of Pontocerebellar hypoplasia associated with RARS2 gene variants include infantile onset, severe psychomotor retardation or regression, drug-resistant epilepsy, and feeding difficulties. The characteristic neuroimaging finding is pontocerebellar hypoplasia. However, its appearance may vary widely with time. The majority of affected children have a poor prognosis.
Humans ; Male ; Female ; Child, Preschool ; Infant ; Child ; Olivopontocerebellar Atrophies/genetics* ; Arginine-tRNA Ligase/genetics* ; Mutation ; Cerebellar Diseases

Adult ; Female ; Humans ; Male ; Olivopontocerebellar Atrophies ; genetics ; Pedigree ; Young Adult

Between 1985and 1987, 31 patients with sporadic olivopontocerebellar atrophy (SOPCA) and 3 patients with familial olivopontocerebellar atrophy (FOPCA) were examined in the Neurologic Clinic of Yongdong Severance Hospital. The incidence of the disease among our neurology clinic patients was 0.9% and 3.4% of those patients were admitted. Seventeen of them were men and seventeen women, and their ages of onset ranged from 16 to 75 years (mean, 48.2 years). In comparison with SOPCA, the disease began earlier in FOPCA (mean age, 51.0 VS 19.3 years), but there were no other differences in clinical feature of the disease. Four patients had parkinsonism, one dementia, and one ophthalmoplegia. None presented spinal involvement or abnormal movements. Eight had a coexisting disease; 3, ch(03)nic alcoholism; 2, hypertension; 2, diabetes mellitus; and 1, malignant neoplasm.
Adolescent ; Adult ; Aged ; Diagnosis, Differential ; Female ; Human ; Korea ; Male ; Middle Age ; Olivopontocerebellar Atrophies/*diagnosis/epidemiology/genetics ; Spinocerebellar Degenerations/*diagnosis