Definition: Deviations from the average values for a specific age and sex in any or all of the following: height, weight, skeletal proportions, osseous development, or maturation of features. Included here are both acceleration and retardation of growth.
Atlas of Clinical Syndromes : A Visual Aid to Diagnosis for Clinicians and Practicing Physicians. (2nd ed.) London:Wolfe Publishing Ltd. 1989. Pp. 198-199.