[Type 28 spinocerebellar ataxia]

Area of Science:

• Genetics
• Neurology
• Rare Diseases

Background:

• Spinocerebellar ataxia type 28 (SCA 28) is a rare, autosomal dominant neurodegenerative disorder.
• It is characterized by progressive cerebellar ataxia, oculomotor disorders, and extrapyramidal symptoms.
• Mutations in the AFG3L2 gene are a known cause of SCA 28.

Purpose of the Study:

• To present a detailed case report of a patient with spinocerebellar ataxia type 28.
• To identify the genetic mutation responsible for the disorder in the patient and her family.
• To describe the clinical presentation, progression, and management of SCA 28.

Main Methods:

• Clinical observation and neurological examination over two years.
• Complete genome sequencing to identify genetic mutations.
• Sanger sequencing to confirm the mutation and analyze family segregation.

Main Results:

• A 21-year-old female presented with a complex phenotype including visual and oculomotor disorders, extrapyramidal syndrome, epilepsy, and cerebellar ataxia, starting at age 14.
• Whole-genome sequencing identified a heterozygous c.838C>T (p.Arg280Trp) mutation in the AFG3L2 gene.
• Segregation analysis confirmed the autosomal dominant inheritance pattern of the AFG3L2 mutation within the family.

Conclusions:

• The study confirms a novel heterozygous mutation in the AFG3L2 gene causing spinocerebellar ataxia type 28.
• This case underscores the diverse clinical manifestations of SCA 28, including early-onset symptoms and a combination of ataxia, movement disorders, and epilepsy.
• Genetic testing is crucial for diagnosing rare neurological disorders like SCA 28 and understanding their inheritance patterns.