1. Department of Pediatrics, Medical Faculty, "Sapienza" University of Rome, Italy
2. San Raffaele Roma, Open University and "Sapienza" University, Rome, Italy
3. Down Syndrome Centre, "Bambino Gesù" Children Hospital, Rome, Italy
4. Department of Pediatric Nephrology, Jagiellonian University Medical College, Krakow, Poland
5. Institute of Biochemistry and Cell Biology, IBBC-CNR, Rome, Italy