1 Division of Rheumatology, and the Unit of Medical Genetics, Laboratory of Cytogenetics and Molecular Genetics, Institute for Research and Health Care (IRCCS), Ospedale Pediatrico Bambino Gesù, Rome, Italy.
2 Pediatric Division, Sant'Eugenio Hospital, ASL Roma 2, Rome, Italy.
3 Division of Rheumatology, and the Unit of Medical Genetics, Laboratory of Cytogenetics and Molecular Genetics, Institute for Research and Health Care (IRCCS), Ospedale Pediatrico Bambino Gesù, Rome, Italy. antonella.insalaco@opbg.net.