Early manifestations of Prader-Willi syndrome: influence of growth hormone.

Pediatricians and neonatologists now understand the clinical picture of Prader-Willi syndrome (PWS) in infants as genetic tools are available to confirm this diagnosis. Hence, an increasing number of very young, still underweight children are being diagnosed with PWS. Some features, such as low prenatal weight and below-average height, subsequent poor growth velocity and increased body fat, possibly in infancy, may be interpreted as a consequence of early growth hormone (GH) deficiency. This raises the question of when is the best time for the initiation of GH treatment. This article presents the results of a study in which ten very young children with PWS (mean age 1.0 year) were treated with exogenous GH. We conclude that GH treatment in young, underweight children, as well as in older children with PWS: (1) normalizes growth and body proportions; (2) probably reduces fat mass and increases muscle mass; (3) may enhance motor development; and (4) is necessary, but obviously not sufficient, to normalize body composition and fat distribution. Whether there is a benefit in treating children with PWS from such an early age requires longer-term studies.