Spinocerebellar ataxia type 23 is an uncommon SCA subtype in the Chinese Han population

A Review of Ocular Movement Abnormalities in Hereditary Cerebellar Ataxias

Cerebellar ataxias are a wide heterogeneous group of disorders that may present with fine motor deficits as well as gait and balance disturbances that have a significant influence on everyday activities. To review the ocular movements in cerebellar ataxias in order to improve the clinical knowledge of cerebellar ataxias and related subtypes. English papers published from January 1990 to May 2022 were selected by searching PubMed services. The main search keywords were ocular motor, oculomotor, eye movement, eye motility, and ocular motility, along with each ataxia subtype. The eligible papers were analyzed for clinical presentation, involved mutations, the underlying pathology, and ocular movement alterations. Forty-three subtypes of spinocerebellar ataxias and a number of autosomal dominant and autosomal recessive ataxias were discussed in terms of pathology, clinical manifestations, involved mutations, and with a focus on the ocular abnormalities. A flowchart has been made using ocular movement manifestations to differentiate different ataxia subtypes. And underlying pathology of each subtype is reviewed in form of illustrated models to reach a better understanding of each disorder.

Spinocerebellar ataxia type 23 (SCA23): a review

Spinocerebellar ataxias (SCAs), formerly known as autosomal dominant cerebellar ataxias (ADCAs), are a group of hereditary heterogeneous neurodegenerative diseases. Gait, progressive ataxia, dysarthria, and eye movement disorder are common symptoms of spinocerebellar ataxias. Other symptoms include peripheral neuropathy, cognitive impairment, psychosis, and seizures. Patients may lose their lives due to out of coordinated respiration and/or swallowing. Neurological signs cover pyramidal or extrapyramidal signs, spasm, ophthalmoplegia, hyperactive deep tendon reflexes, and so on. Different subtypes of SCAs present various clinical features. Spinocerebellar ataxia type 23 (SCA23), one subtype of the SCA family, is characterized by mutant prodynorphin (PDYN) gene. Based on literatures, this review details a series of SCA23, to improve a whole understanding of clinicians and point out the potential research direction of this dysfunction, including a history, pathophysiological mechanism, diagnosis and differential diagnosis, epigenetics, penetrance and prevalence, genetic counseling, treatment and prognosis.

Spinocerebellar ataxia type 13 is an uncommon SCA subtype in the Chinese Han population

The spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders, among which SCA subtype 13 (SCA13) was found associated with mutations in the KCNC3 gene. Among 522 Chinese Han SCA patients (including familial and sporadic) we have collected since 1995, approximately 40% of them have not yet been assigned genotype. To investigate the mutation frequency of KCNC3 in SCA patients from mainland Chinese Han population, we analyzed the KCNC3 gene in 201 unrelated patients diagnosed with dominantly inherited cerebellar ataxia using the denaturing high-performance liquid chromatography (DHPLC) method. All analyzed samples displayed the normal elution profile, which denoted that no disease-related mutation was identified, suggesting that SCA13 be a rare form of SCA in mainland China.