Progressive Axonal Neuropathy and Cerebellar Ataxia Associated with Homozygous Pathogenic POLG Mutation in a Patient of African Descent from Northern Minas Gerais/Jequitinhonha Valley, Brazil: A Case Report and Epidemiological Implications.
Caroline Fernandes Melo, Laura Toledo de Vasconcelos, Lays Aparecida Bono Evangelista
✦ AI-curated · Sources linked
Case in brief
A 41-year-old man of African descent presented with progressive axonal sensorimotor neuropathy, cerebellar ataxia, dysarthria, and oculomotor abnormalities. His condition was confirmed as mitochondrial DNA depletion syndrome type 4B due to a homozygous pathogenic POLG mutation. Despite the severity of symptoms, he exhibited clinical and electrophysiological stability over 2.5 years, suggesting a favorable disease course.
What made this case unusual
This case is notable for the identification of the p.Trp748Ser POLG mutation in a patient of African descent, challenging the mutation's presumed ethnic exclusivity and highlighting the impact of consanguinity in genetic disorders.
Diagnostic / clinical pearl
Clinicians should consider POLG-related ataxia in patients of non-European ancestry who present with axonal neuropathy and cerebellar signs, as genetic variants may not be limited to specific ethnic groups.
Why it matters
This case emphasizes the need for greater representation of diverse populations in genetic research to improve diagnostic accuracy and understanding of hereditary conditions.