Osteopetrosis and Glanzmann's thrombasthenia in a child.

Autosomal recessive osteopetrosis is a rare, fatal disease characterized by accumulation of excessive bone mass due to defective bone resorption. The pathogenesis of osteopetrosis is controversial. Osteoblast-osteoclast interaction defects, incorrect differentiation of osteoclasts, abnormal contact between osteoclast and extracellular matrix, and abolished signaling are included in this process. Recently, mutations in the gene of the vacuolar proton pump have been described in some cases of recessive osteopetrosis. Glanzmann's thrombasthenia (GT) is a rare hereditary qualitative platelet disorder characterized by a lifelong bleeding tendency due to quantitative and qualitative abnormalities of the platelet integrin alpha(IIb) beta3. Several mutations on either integrin alpha(IIb) [glycoprotein (GP) IIb] or integrin beta(3) (GP IIIa) were reported in GT. We report on a patient with autosomal recessive osteopetrosis concurrently diagnosed with variant type Glanzmann's thrombasthenia. To our knowledge, our patient was the first case reported in the literature in which osteopetrosis and Glanzmann's thrombasthenia were diagnosed together.