Nail-Patella Syndrome (Osteo-Onychodysplasia; Arthro-Onychodysplasia; Onycho-Osteodysplasia) By Frank Pessler, MD, PhD, Helmholtz Centre for Infection Research Reviewed / Revised Dec 2022 View Patient Education Symptoms and Signs Diagnosis Treatment Nail-patella syndrome is a rare inherited disorder of mesenchymal tissue characterized by abnormalities of bones, joints, fingernails and toenails, and kidneys.