The purpose of the protocol is to describe the distribution of IGF-1 deficiency in the studied population of Idiopathic Short Children without Growth Hormone Deficiency or any other identified cause of short stature and not treated with recombinant Growth Hormone or IGF-1

Inclusion Criteria:

• Short children, height ≤ -2.5 SDS
• Age ≥ 2 years
• With at least one normal or elevated peak GH response to a stimulatory test (peak GH ≥ 7 ng/mL) at the time of the study and/or at a given time-point during the last 12 months
• Pre-pubertal
• Signed Informed Consent, including agreement to have blood samples taken for hormonal measurement and genetic analysis, by both parents or by Legally Acceptable Representatives when applicable and the child when applicable

Exclusion Criteria:

• The following identified causes of short stature:
• GH-deficient short stature
• Other endocrine causes (hypothyroidism, Cushing's syndrome, parathyroid or vitamin D disorders, hypogonadism)
• Identified syndromes with genetic abnormalities (including Turner, Noonan and Russell-Silver syndromes)
• Chronic diseases including malnutrition, coeliac disease, chronic inflammation, muscular dystrophy, thalassaemia, blood disorders, severe liver or kidney disease and severe cyanotic heart disease
• Chronic diseases requiring treatment with chronically administered corticosteroids
• Skeletal dysplasia
• Psychosocial short stature
• Patients having received irradiation, including total body irradiation
• Patients currently on GH or IGF-1 therapy or having received GH or IGF-1 therapy in the last 12 months
• Patients likely to require GH, IGF-1 or chronic corticosteroid treatment during the study
• Any mental condition that prevents both parents or Legally Acceptable Representatives and the child when applicable from understanding the nature, scope and possible consequences of the study, or any evidence of an uncooperative attitude

Idiopathic Short Stature children