The spontaneous growth of 315 patients (109 girls and 208 boys) with Prader-Willi syndrome (PWS) was analysed in a mixed longitudinal and cross-sectional manner. 33 patients were seen in the department between 1970 and 1994; height and weight of 76 patients from Germany were evaluated by means of a questionnaire with detailed measuring instructions, and 206 definite cases were added from the literature. Mean ( SD) length of newborn babies with PWS was 50.2+/-2.8 cm (145 boys) and 48.9 3.3 cm (79 girls). Mean weight at birth was 2945 570 g in boys and 2782+/-594 g in girls. During the 1st year, the children's growth was nearly normal, thereafter short stature was present in approximately 50% of PWS patients. Between 3 and 13 years of age, the 50th percentile for height in PWS is roughly identical with the 3rd percentile in healthy controls. Body weight was normal for all boys and girls during the first 2 years. Thereafter, a rapid weight gain occurred; after an age of 10 years weight-for-height index in nearly all patients exceeded the normal range. The extent of pubertal growth was reduced for the group. Mean adult height was 161.6+/-8.1 cm (23 males) and 150.2+/-5.5 cm (21 females). Head circumference for age was normal for boys and girls.
Conclusion: Reference data on spontaneous development of growth and weight gain of children with Prader-Willi syndrome are described allowing a better counselling of patients and parents.