Dystonia was the second most common sign after encephalopathy. The BFMDS questionnaire was administered to 34 SLC19A3 patients with dystonia (9.8 ± 1.6 points [mean 6 SEM]; range, 0–30). Higher BFMDS scores were identified in patients who had a previous history of developmental delay and in patients with disease onset before 6 months of age. A positive, and almost significant, correlation was observed between the BFMDS scores and the time from disease onset to thiamine initiation. This evidence concerns the gene SLC19A3 and Global developmental delay.