It is understandable but unfortunate that physicians often adopt a fatalistic attitude toward hereditary diseases. It is true, of course, that we cannot change patients' genetic makeup. Yet, it is often forgotten that some of the diseases which are most effectively treated in medicine are now recognized to be, at least in large part, of genetic origin. Diabetes mellitus, pernicious anemia, and hereditary spherocytosis all belong to this group.
There is, moreover, a largely untapped potential for the prevention of the sequalae of two hereditary diseases, phenylketonuria and galactosemia. In the case of phenylketonuria a diet low in phenylalanine is believed to improve markedly the outlook of the affected infant. Similarly, a diet low in galactose prevents the development of the clinical features of galactosemia. In both instances, it is necessary for the therapeutic diet to be instituted very early in life; otherwise, its value is lost. Thus, early detection
SCREENING FOR GALACTOSEMIA AND PHENYLKETONURIA. JAMA. 1964;190(13):1126. doi:10.1001/jama.1964.03070260038015