Predictive Value of the Insulin-like Growth Factor-1 (IGF-1) Generation Test for the Growth Response to Growth Hormone Treatment (PRED-IGF)

Inclusion Criteria

• •Age 2.0 - 9.0 years for females, 2.0 - 10.0 yrs for males.
• •Prepubertal stage (Tanner 1 for breast (B1) in females, or Tanner 1 for genitals (G1) for males).
• •Bone age \< 10 'years' (males) or \< 9 'years' (females) according to Greulich and Pyle. The bone age will be read by the pediatric endocrinologist responsible for the pre-study screening visit.
• •Height SDS \< -2.5 for ethnically adequate references. For children of Dutch or Western European origin the 1997 nation-wide references for Dutch children will be used. For children of Moroccan or Turkish origin, the respective reference charts will be used. For children of other ethnicities, the 1977 North American (NCHS/WHO) reference will be used, as these charts have been accepted by WHO as world-wide standard from the age of 5 years.