TPK1 and FG syndrome: On the one hand, TPK1 acts as a homodimer and catalyzes the conversion of thiamine-to-thiamine pyrophosphate, a cofactor for some enzymes of the glycolytic and energy production pathways (oxidation and lipogenesis). TPK1-related disorders comprise thiamine metabolism dysfunction syndrome, abdominal obesity-metabolic syndrome, limb-girdle muscular dystrophy, Opitz-Kaveggia syndrome, dystonia, epilepsy, and autism spectrum disorder [21].