Table 1.

Clinical features and diagnostic work-up at birth.

Prenatal history	Reduction of fetal movements Postnatal growth failure
Clinical Examination	Generalized hypotonia, failure to thrive. Bitemporal narrowing, frontal bossing, dolichocephaly, micrognathia bilateral ptosis. Left cryptorchidism.
METABOLIC WORK-UP
Plasmatic amino acids Urinary organic acids Ammonium Lactate Acid/base status	Normal for age
GENETIC TESTS
Karyotype CGH array Prader Willi Syndrome	46, XY Normal No deletion on chromosome 15
NEUROLOGIC TESTS
Cerebral ultrasound Spinal and cerebral MRI EMG	Normal
Cardiologic examination	Patent foramen ovale (POF, 1 cm) with left-right shunt and atrial septum aneurysm.
Abdominal ultrasound	Dilatation of the left renal pelvis and ureter (POM), with an antero-posterior pelvic diameter of 0,8 cm, a ureteric diameter at bladder junction of 0,7 cm and normal renal parenchyma and bladder.