Progressive Slurred Speech as an Atypical Presentation of GDAP2-Related Spinocerebellar Ataxia: A Case Report.

A 47-year-old man with diabetes mellitus and dyslipidemia developed progressive slurred speech over four years. MRI revealed no cerebellar atrophy, and routine laboratory and neurophysiological investigations were unremarkable. His brother exhibited similar but advanced symptoms, including dysphagia and severe gait impairment, leading to wheelchair dependence. Whole-exome sequencing identified a likely pathogenic homozygous nonsense mutation in the GDAP2 gene, confirming a diagnosis of autosomal recessive spinocerebellar ataxia type 27 (SCAR27). This report emphasizes the importance of considering hereditary ataxias in the differential diagnosis of progressive dysarthria, even in the absence of striking ataxic signs or neuroimaging abnormalities. Early genetic testing can prevent unnecessary investigations, facilitate appropriate counselling, and improve the understanding of rare neurological conditions. Identifying novel mutations contributes to delineating the full clinical spectrum of SCAR27 and may guide research into targeted therapeutic strategies.