Multifocal Osteolysis, Nodulosis, and Arthropathy in a Saudi Boy with Osteoporosis and Short Stature
Hatoun Elazhary, Abdulmoein Al Agha
MONA syndrome, characterized by multifocal osteolysis, nodulosis, and arthropathy, is a rare autosomal recessive disease, with only 44 cases reported worldwide. Clinically, MONA syndrome presents as a progressive deformity of the hands and feet, with soft nodules developing in the palm of the hands and foot pad, with osteolysis of the carpal and tarsal bones. As such, MONA syndrome is frequently diagnosed incorrectly as polyarticular juvenile idiopathic arthritis, leading to late diagnosis and the potential for the development of severe complications. We describe the case of a 7-year-old boy who was misdiagnosed with juvenile idiopathic arthritis rather than MONA syndrome. The child initially presented with progressive arthropathy, with negative inflammatory markers, leading to the diagnosis of juvenile idiopathic arthritis and initiation of anti-human necrotic factor and anti-inflammatory treatment. MONA syndrome was diagnosed based on radiological and genetic assessments performed when treatment provided no benefit. Ultimately, the course of MONA syndrome in this child was complicated by osteoporosis and short stature. Careful evaluation to a child presenting with MONA syndrome will lead to accurate diagnoses while avoiding unnecessary management.