The Laurence-Moon-Biedl syndrome shows much variation in its clinical picture from case to case and the limits of this syndrome are indefinite. This clinical entity was first identified by J. Z. Laurence and R. C. Moon in 1866 and was more completely described by A. Biedl in 1922. In 1935, Cockayne, Krestin and Sorsby stated that some 30 isolated cases and 15 affected families were reported during the ten years from 1925 to 1935, and in 1939 Sorsby, Avery and Cockayne made a later review. In October, 1955, J. Todd described a case of Laurence-Moon-Biedl syndrome with paranoid psychosis in the American Journal of Mental Deficiency, and in 1950 R. A. Burn reviewed 82 cases giving the total number of reported cases as 260. Up to 1957 about 320 cases have been described in the world literature but even this number is likely to rise with the increased interest shown in this syndrome.