The purpose of this study is to estimate the sensibility at the growth hormone in vivo at the children presenting a Prader-Willi syndrome (SPW) in comparison with children presenting a deficit in growth hormone (GHD).

Estimate the sensibility at the growth hormone in vivo at the children presenting a Prader-Willi syndrome (SPW) in comparison with children presenting a deficit in growth hormone (GHD) by the measure of the circulating rates of IGF-I under treatment.

Inclusion Criteria:

1. SPW and SPW-B :

   • Female or male child of age > or = 1 year
   • Child naïve of treatment by GH and that must begin a treatment with GH
   • Child covered by a national insurance scheme or an equivalent
   • Signature of the informed consent by one of both holders of the parental authority

2. GHD :

   • Female or male child of age > or = 1 year
   • Child paired for the age (+/-on 1 year) and for the sex with regard to the group SWP
   • Child presenting a GH* deficiency defined by :

   Growth criteria of size (size) < 2 DS) Criteria of speed of growth (speed of growth < 1 DS over the last year) 2 tests of pharmacological stimulation of GH with peak GH max < 20 mUI

   • Child naïve of treatment by GH and that must begin a treatment with GH
   • Child covered by a national insurance scheme or an equivalent
   • Signature of the informed consent by one of both holders of the parental authority * The deficit in GH can be isolated or associated with one or several other hormonal deficits: deficit in TSH, deficit in ACTH, deficit in LH-FSH, deficit in prolactin. The child GHD can thus receive other treatments associated with the growth hormone.

3. T : controls

   • Female or male child of age > or = 1 year
   • Child paired for the age (+/-on 1 year) and for the sex with regard to the group SWP
   • Child hospitalized at the hospital of the children of the University Hospital of Toulouse for a programmed surgical operation
   • Child covered by a national insurance scheme or an equivalent
   • Signature of the informed consent by one of both holders of the parental authority

4. SPW-GH-B :

   • Female or male child of age > or = 1 year
   • Child hospitalized for a programmed surgical operation
   • Child covered by a national insurance scheme or an equivalent
   • Child treated with GH for at least 3 month
   • Signature of the informed consent by one of both holders of the parental authority

Exclusion Criteria:

1. SPW and GHD

   • Child presenting a contraindication to the taking of growth hormone :
   • Growth cartilage welded
   • Tumoral pathology in process of evolution
   • Corticosteroid therapy (not substitute)
   • Allergy known about solvent
   • Badly balanced diabetes
   • Child presenting a hypersensitivity to the active principle or to one of the excipients of Genotonorm ® or Omnitrope ®
   • Child presenting a severe obesity (defined by a report weight / size > 200 %)
   • Child presenting clinical signs ENT (snores associated with a hypertrophy of the adenoids vegetations and\or the tonsils)
   • Child presenting clinical signs evoking a respiratory illness of the sleep (night-respiratory snores, respiratory breaks during the sleep)

2. SPW-B:

   • Child presenting a hypersensitivity to the local anaesthetic with amide connecion
   • Child presenting a hypersensitivity to the components of the bandage Emlapatch®
   • Child presenting a hypersensitivity to one of the components of the lidocaïne aguettant without conservative®
   • Child presenting a porphyria
   • Child presenting a congenital methemoglobinemia
   • Child presenting a contraindication to Meopa : patients requiring a ventilation in pure oxygen, intracranial High blood pressure, Any change of the state of consciousness, preventing the cooperation of the patient, Pneumothorax, Bubbles of emphysema, Gaseous embolism, Accident of dive, abdominal gaseous Distension, Patient having received recently an ophthalmic gas (SF6, C3F8, C2F6) used in the eye surgery as long as persists a bubble of gas inside the eye and at least during a period of 3 months. Grave postoperative complications can arise in touch with the increase of the pressure intraocular, facial Traumatism interesting the region of application of the mask

3. T : controls

   • Chronicle pathology in which an abnormality of growth would be involved
   • Other hormonal abnormalities
   • Children receiving a treatment on the long range, corticosteroid therapy in particular, being able to interfere with the sensibility to GH or to the insulin
   • Holder of the parental authority under supervision, guardianship or under protection of justice
   • Participation in another study simultaneously at this one