Triosephosphate isomerase deficiency is an autosomal recessive disorder characterized by progressive neuromuscular degeneration, seizure, dystonia, weak muscles, cardiomyopathy, hemolytic anemia, and death in early childhood. In the glycolytic pathway, dihydroxy acetone phosphate (DHAP) is converted to glyceraldehyde-3-phosphate by an enzymatic reaction. The reaction is catalyzed by the TPI enzyme. In TPI deficiency, erythrocyte viability is reduced due to insufficient anaerobic respiration and DHAP accumulation causes toxic effects on cells. A 2-month-old boy initially presented with infection and moderate anemia. Respiratory distress and neurological symptoms developed shortly thereafter. He was followed up with a mechanical ventilator for a long time. A homozygous pathogenic variant in the TPI1 gene was detected in the genetic analysis performed due to the progressive neurodegeneration and the need of intermittent erythrocyte transfusion in the follow-up. Here, an infant case with triosephosphate isomerase enzyme deficiency is presented.