Criteria have also been defined that identify patients who do not require reassessment of GH status because of a high likelihood of ongoing severe GH deficiency, that is, those with: (i) multiple pituitary hormone deficiencies (i.e. three or more) plus low serum IGF-I levels (≤2 SDS); (ii) genetic defects affecting the hypothalamic–pituitary axis; or (iii) lesions of the hypothalamic–pituitary area (42). Here, IGF1 is linked to hypopituitarism.