Clinical features including lactic acidosis, diabetes, cataract, neuropathy, and proximal myopathy combined with cerebellar ataxia, progressive spastic-ataxic gait, hyperkinetic movement disorders, and pontine/cerebellar atrophy were among the signs of the defective LETM1 phenotype that are not typical of WHS; instead, they are more typical of archetypal mitochondrial disorders. The gene discussed is LETM1; the disease is lactic acidosis.