Dados do Trabalho

Título

Spinocerebellar ataxia 17 of accelerated evolution

RESUMO

Patient, male, 35 years old, previously healthy, parents healthy and not consanguineous, started at age 32 with a complaint of imbalance, characterized by an insidious and progressive cerebellar ataxic syndrome, and in less than 6 months of progression, he already depended on walking support. Associated with this, he presented with amnestic and dysexecutive mild cognitive impairment, in addition to depressive-type mood disorder. In the same period, he started with epileptic seizures characterized by behavioral arrest and sphincter release, without motor tremors. Due to the accelerated progression of neurological symptoms, despite the innocent cerebrospinal fluid, intravenous immunoglobulin was performed for 5 days, thinking about autoimmune encephalitis, but without improvement. Advanced brain neuroimaging showed pancerebellar atrophy without contrast enhancement. Genetic testing confirmed it to be Spinocerebellar Ataxia type 17 (SCA 17).

Discussion
SCA 17 is a rare, autosomal dominant genetic disease identified by the abnormal expansion of the CAG/CAA repeat in the TATA-box-binding protein (TBP) gene, with affected individuals having more than 41 repeats. The clinical manifestation begins between 3 and 75 years (mean: 34.6 years), being defined by cerebellar ataxia (95%), cognitive symptoms (90%), psychiatric symptoms, epilepsy, and involuntary movements (chorea, dystonia). By 2005, fewer than 100 families had been reported to have the disease worldwide. Treatment is currently limited to controlling symptoms, improving quality of life, but there is still no cure.

Conclusion
Genetic tests are increasingly gaining space and usefulness in clinical practice, elucidating cases and directing conducts, which, although often not curative, are substantial for the individual and family. In this specific case of SCA 17, by configuring an autosomal dominant inheritance, it made it possible to structure a family genetic counseling that would guide the family, since the patient had siblings and children.