Abnormal mitochondria in acidemia. Coloured transmission electron micrograph (TEM) of a section through tissue showing abnormally shaped and structured mitochondria in the liver of a mutant mouse with liver disease that mimics the same condition in patients with methylmalonic acidemia (MMA) - a metabolic disorder that disrupts normal amino acid metabolism. Recent study have shown that findings involving elevated hormones and liver problems in mice with methylmalonic acidemia can be applied to human patients with the disease.