Osteopetrosis in two siblings: two case reports

Limited Reconstructive Options of Jaw Osteomyelitis in the Osteopetrosis Patient Complicated by Blood Dyscrasia

Osteopetrosis is a rare systemic skeletal disorder characterized by increased bone density and mass resulting from suboptimal or impaired resorption of osteoclastic bone. Compromised bone marrow function and associated disorders of red blood cells contribute to hematopoietic abnormalities, which exacerbate the risk of complex, recurrent infections such as jaw osteomyelitis. This case report describes the treatment of a 68-year-old Korean female with autosomal-dominant osteopetrosis who presented with severe and persistent jaw osteomyelitis complicated by hematopoietic dysregulation. Clinical findings included skin necrosis, purpura, and ecchymosis, which were likely due to underlying hematopoietic insufficiency and impaired wound healing. Despite suboptimal conservative interventions, partial mandibulectomy was ultimately unavoidable. Reconstruction was performed with a pectoralis major myocutaneous flap, as microvascular and osteocutaneous flaps were not viable due to limitation of the patient's vessels and bone marrow. Conservative debridement, rigorous wound care, and transfusion support were essential to manage the infection and promote healing. This case underscores the challenges of treating osteomyelitis in patients with osteopetrosis, particularly given the likelihood of systemic hematopoietic compromise and a suboptimal healing environment. Conservative approaches, supportive transfusions, and close monitoring of the skin and hematological complications are vital for achieving favorable outcomes.

Infantile osteopetrosis with delayed development, organomegaly and wandering eyes: case report

Osteopetrosis encompasses rare inherited metabolic bone disorders with defect in the osteoclast activity. Severe forms of presentation such as malignant infantile osteopetrosis are seen in infants and milder forms in older children. The clinical presentation includes failure to thrive, severe pallor, optic atrophy and hepatosplenomegaly. The disorder is characterised by dense bone on radiography, hence the name marble bone disease. A 10-month-old boy who presented with developmental delay, failure to thrive, nystagmus (which the mother described as wandering eye movements), splenomegaly of 16 cm and hepatomegaly of 8 cm. Investigations demonstrated severe anaemia (5.7 g/dL) and thrombocytopenia (34 x 109/L). Radiological signs which help in the diagnosis include diffuse sclerosis, bone within bone appearance, sandwich vertebrae and Erlenmeyer flask deformity. Plain radiography is an easily available and cost effective tool which can aid in the diagnosis of osteopetrosis.

Progressive skeletal defects caused by Kindlin3 deficiency, a model of autosomal recessive osteopetrosis in humans

The cellular and molecular mechanisms of bone development and homeostasis are clinically important, but not fully understood. Mutations in integrins and Kindlin3 in humans known as Leukocyte adhesion deficiencies (LAD) cause a wide spectrum of complications, including osteopetrosis. Yet, the rarity, frequent misdiagnosis, and lethality of LAD preclude mechanistic analysis of skeletal abnormalities in these patients. Here, using inducible and constitutive tissue-specific Kindlin3 knockout (K3KO) mice, we show that the constitutive lack of embryonic-Kindlin3 in myeloid lineage cells causes growth retardation, edentulism, and skull deformity indicative of hydrocephaly. Micro-CT analysis revealed craniosynostosis, choanal stenosis, and micrognathia along with other skeletal abnormalities characteristic of osteopetrosis. A marked progression of osteosclerosis occurs in mature to middle-aged adults, resulting in the narrowing of cranial nerve foramina and bone marrow cavities of long bones. However, postnatal-Kindlin3 is less critical for bone remodeling and architecture. Thus, myeloid Kindlin3 is essential for skeletal development and its deficiency leads to autosomal recessive osteopetrosis (ARO). The study will aid in the diagnosis, management, and treatment choices for patients with LAD-III and ARO.

Intermediate Autosomal Recessive Osteopetrosis With an Unusual Absence of Fractures

Background: Osteopetrosis includes a variety of rare inherited skeletal disorders characterized by increased bone density and thickness. It has different clinical forms, including infantile autosomal recessive, intermediate autosomal recessive, and late-onset autosomal dominant forms. Intermediate autosomal recessive osteopetrosis (IARO) displays high variability. Case Report: A 10-year-old male presented to our pediatrics emergency department with abdominal distension, low-grade fever, and swelling of the right maxilla with associated discharge. His local physician had treated the lesion with drainage and aspiration of pus without improvement. Examination revealed pallor, hepatosplenomegaly, poor dentition, and dental caries. Eye examination showed reduced visual acuity, absent color vision, nystagmus, and bilateral optic nerve atrophy. Laboratory investigations showed anemia and thrombocytopenia. Radiography yielded classic features of osteopetrosis. Detailed intraoral examination revealed an area of exposed necrotic bone in the alveolar region of the right maxilla, leading to a diagnosis of IARO with underlying osteomyelitis. The intraoral wound was treated with bismuth iodoform paraffin paste dressing, and the infection was treated with antibiotics. Anemia and thrombocytopenia were managed supportively by transfusion of packed red blood cells and platelets. Conclusion: IARO commonly presents with multiple fractures, so the absence of fractures in our patient was unusual. Studies evaluating the intermediate variant are meager; hence, documenting its various presentations is essential to aid physicians in making early diagnoses. Osteomyelitis of the jaws is a feared complication in these patients. Therefore, practitioners need to be cautious of infections of dental origin.