Rare Cause of Bone Marrow Failure: Osteopetrosis, Case Series

Osteopetrosis is a rare metabolic bone disease that can lead to progressive bone marrow failure if left untreated. Resulting cytopenia and extramedullary hematopoiesis are frequently encountered in autosomal recessive form of the disease (ARO) and may result in death. Recurrent bone fractures and skeletal deformities are mostly seen in autosomal dominant form osteopetrosis (ADO) and cause significant morbidity. In this report, clinical, laboratory, and radiological findings of 5 patients with osteopetrosis were presented. Three had cytopenias, typical peripheral smear, and bone marrow aspiration findings regarding bone marrow failure as well as extensively increased bone density which was a classical radiological appearance. Two of them had <i>TCIRG1</i> mutations associated with ARO, died because of severe infections. One with certain findings of ARO without genetic analysis is alive after hematopoietic stem cell transplantation. Two siblings had novel variants of <i>CLCN7</i> (NM_001114331) p.Val755Serfs*4 (c.2263del) heterozygocity, associated with ADO and severe skeletal problems. One had been followed up also for nephrotic syndrome. Detection of genetic abnormalities is important as well as typical physical examination findings and, presence of hematological or radiological indicators in definitive diagnosis of the disease. Although osteopetrosis is rare, it is a potentially fatal disease that should be considered in the differential diagnosis.