Nickan Research Institute Journal of Parathyroid Disease 2345-6558 14 1 2026 01 01 Pyle’s disease in a 4-year-old boy; a rare case report e13310 e13310 10.34172/jpd.2025.13310 EN Nosrat Ghaemi https://orcid.org/0000-0002-2405-1916 Sepideh Bagheri https://orcid.org/0000-0001-6750-2214 Samaneh Norouzi https://orcid.org/0000-0002-0836-3514 Sara Nikpour https://orcid.org/0000-0003-1986-3992 Journal Article 10.34172/jpd.2025.13310 2025 10 20 2025 12 06 Pyle’s disease (PD) is a rare inherited skeletal dysplasia. Approximately 35 cases have been reported worldwide. It is more frequently reported in adults. This skeletal dysplasia has distinct radiologic features, which are characterized by widening of the distal metaphysis of the femur and proximal tibia, cortical thinning, and osteoporosis. Regarding the rarity of PD and the importance of reporting its presentations, we aimed to report a 4-year-old boy focusing on its radiographic, laboratory, and genetic findings. In this case report, we present a 4-year-old boy from consanguineous parents brought to the pediatric orthopedic clinic for abnormal shape of lower extremities and difficulty walking when he was 3 years old. He was evaluated and finally diagnosed with PD using whole exome sequencing.