DAT-SPECT findings in POLR3A-related striatal variant: a case report and literature review.

The POLR3A striatal variant manifests with prominent extrapyramidal signs, ranging from early-onset dyskinetic syndromes to juvenile parkinsonism. This case report offers the first DAT SPECT evidence of nigrostriatal involvement, revealing significant reductions in striatal binding and decreased putamen-to-caudate ratios. These findings provide preliminary in vivo functional evidence of presynaptic dopaminergic involvement, offering a valuable biological correlate for the clinical phenotype.