The Biochemical Nature of Disease

The physician sees patients who complain of symptoms, and, in order to provide rational therapy, he must anive at a correct diagnosis. Accordingly, the physician takes a medical history, performs a physical examination, and obtains whatever laboratory studies are deemed necessary. The physician uses his findings to provide a diagnosis, therapy, and a prognosis. This classical approach to the practice of medicine is depicted in Fig. 1. 

Robert H. Herman Endocrine-Metabolic Service, Letterman Army Medical Center, Presidio of San Francisco, California 94129. Robert M. Cohn Department of Metabolic Research, Children s Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania 19104. 

Multiple gene defects may arise in the various chromosomal disease syndromes. In many cases the relationship between the chromosomal abnormality and the clinical expression is quite clear. In other 

Abnormal hormonal state hyper- or hypoendocrine function 

If a nutritional deficiency or excess occurs, the intermediary metabolic pathways may be affected sufficiently to result in an abnormal physiological state and ultimately in disease. Thus, a protein deficiency leads to kwashiorkor, while an excess of vitamin D leads to a toxic state. Without the proper substrates in the complex metabolic pathways which constitute the intermediary metabolic processes, the entire biochemical system will be unable to function despite the intrinsic normality of the pathways. Clearly, nutritional deficiencies and excesses can lead to disease which is biochemical in nature. 

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