Osteopetrosis is a rare genetic disorder. Defective osteoclast function causes increased bone mass. It can occur in varying severity from mild forms that are asymptomatic to fatal forms. T-cell immune regulator 1 mutation has been associated with malignant forms of autosomal recessive osteopetrosis. Rarely, mild clinical forms associated with this mutation have been reported in the literature. We present a case of osteopetrosis with a mild clinical course presenting with a fracture, no hematologic and neurological pathologies, and a new T-cell immune regulator 1 mutation. We think that the clinician should keep in mind the differential diagnosis of osteopetrosis in patients presenting with skeletal anomalies, pathological fractures, and increased bone mineral density, even if they do not have neurological or hematological symptoms in early adulthood.
Cite this article as: Arslan Cellat EG, Akarsu E, Sayiner ZA, Kördüğüm A. Novel mutation in T-cell immune regulator 1: A case of adult-onset autosomal recessive osteopetrosis. Turk J Endocrinol Metab. 2022;26(4):221-223.