Prader-Labhart-Willi syndrome: auxological response to a conventional dose of growth hormone in patients with classical growth hormone deficiency.

The aim of the study was to evaluate the effect of growth hormone (GH) (14 IU/m2/week) on height, body mass index and predicted adult height in children with Prader-Labhart-Willi (PLWS) syndrome and GH deficiency. - By auxological criteria GH deficiency was suspected in 10 patients (age: 7-16 years). In 9 patients two GH provocative testings and MR imaging of the pituitary were performed. IGF-I measurements, bone age determinations, body mass index (BMI), height standard deviation score, height velocity -SDS and predicted adult height (PAH) were determined before and during GH treatment. Nine patients could be followed for up to 2 years, 3 patients for 4 years and 2 patients for 5 years of GH treatment. - Predicted adult height could be calculated in all after 1 year of treatment and was on average 11.6 cm below target height (-17.6 to +2.5 cm). GH treatment in a conventional dose (14 IU/m2/week) in daily subcutaneous injections was performed. Height SDS improved from -3.47 to -2.27 after 2 years of treatment, height velocity SDS from -1.74 to +2.65 after 1 year and remained +1.78 after 2 years. PAH increased on average by 5.1 cm. BMI was unchanged during 2 years. Bone age development was appropriate with +2.13 years after 2 years. In 2 patients who were treated with GH for up to 5 years and in 1 who was treated up to 4 years, the positive effect on height SDS and height velocity SDS persisted. - In conclusion GH treatment in a conventional dose (14 IU/m2/week) in PLWS patients with GH deficiency is effective over a period of 2 years in regard to height development and predicted adult height but ony limited in regard to changes in BMI.