Every characteristic of human anatomy and physiology is determined by biochemical reactions catalysed by enzymes. These in turn are determined by our genetic make-up. If a gene is defective or missing it will result in a defective or missing enzyme—a so-called Inborn Error of Metabolism. In a pathway a → b → c → d, if the enzyme that converts c to d is defective, or missing, d cannot be made and c may accumulate so that abnormal concentrations may build up—perhaps in the blood or urine. Knowledge of the defective enzyme and its gene(s) may make possible the rational treatment of the resulting disease. The Inborn Errors of Metabolism map identifies the sites of over 40 such metabolic deficiency diseases which are named on the sides of the map.

The new edition of the Inborn Errors of Metabolism Map is now available!

Please click the image above to view/download the PDF version. A GIF version of the map is available by clicking here. In the GIF version, further details of the enzymes implicated in the various diseases of metabolism can be displayed by clicking on their EC numbers, which are shown in the side panels on either side of the chart.