Homozygous or compound heterozygous mutations within the TPI1 gene result in the rare enzymopathy, TPI deficiency, which presents clinically with chronic haemolytic anaemia, cardiomyopathy, increased susceptibility to infections, neurodegeneration and death in early childhood (Sarper et al., 2013; Rosa et al., 1985; Fermo et al., 2010). The gene discussed is TPI1; the disease is triosephosphate isomerase deficiency.