PWS European Blood Bank for Infants and Controls From 0 to 48 Months

Study of Early Endocrine Profile in Infants With Prader-Willi Syndrome (PWS) in Order to Unravel the Switch From Early Feeding Difficulties to Obesity and Hyperphagia.

The present project aims to determine the underlying mechanisms for the switch from failure to thrive to excessive weight gain and hyperphagia with impaired satiety in PWS. The primary objective is to describe the evolution of circulating hormones involved in feeding and appetite regulation during the 4 first years of life. The secondary objective is to make this blood bank available for other research projects and particularly the investigation of hormones involved in hypogonadism.

Over the last ten years, the age at diagnosis in PWS has fallen significantly and the majority of cases is now diagnosed during the 1st trimester of life giving the possibility to collect precise clinical data and serum samples at early stages. The investigators of the project are involved in the care of patients with PWS and have a devoted clinic and an organized network in their country through clinical networks or patient associations.

The investigators propose to perform a prospective multicentric study, both longitudinal (duration 30 months) and cross-sectional with implementation of a blood bank in link with a multicenter database including clinical data on birth, auxology, endocrine functions and feeding behaviour. The cohort will include 200 infants from 3 to 48 months with PWS and 200 controls matched on age recruited in the 6 participating countries. The investigators make the assumption that 3 blood sampling will be necessary during the first year and 6 monthly sampling thereafter. For measuring hormones and neuropeptides (ghrelin, insulin, leptin, pancreatic polypeptide, oxytocin, cortisol, melatonin, orexin A, GLP-1 and PYY) involved in feeding and appetite regulation the investigators will use primarily multiplex microplates technics requiring 50-200µl of sample. Intragroup and intergroup comparisons will be performed in order to describe the evolution of each hormone with time and to compare data obtained in the PWS group with those obtained in the control group.

Inclusion Criteria (PWS infants cohort)

• Genetic diagnosis of Prader-Willi syndrome

Exclusion Criteria (PWS infants cohort)

• none

Inclusion Criteria (control group)

• children hospitalized for a planned surgery for malformation, orthopaedic or visceral surgery

Exclusion Criteria (control group)

• children with endocrine disorder