IN THE Croonian Lectures delivered at the Royal College of Physicians in 1908, Sir Archibald Garrod suggested that four metabolic disorders—albinism, alkaptonuria, cystinuria and pentosuria—had certain features in common. First, in all four conditions the onset of the particular abnormality could be dated to the first days or weeks of life, especially when a special effort was made to do so. A second characteristic was their familial occurrence in a considerable number of cases. A third feature was that the conditions were relatively benign and compatible with a normal life-expectancy. A fourth feature, noted by other clinicians in Garrod's day, was the frequency with which these disorders occurred among the offspring of consanguineous marriages.
During the past decade, we have witnessed tremendous progress in our understanding of the "inborn errors of metabolism" and some of the conditions can be considered an integral part of clinical medicine. Methods of treatment have