[Case example: malignant infantile osteopetrosis--pathogenesis and therapeutic options].

Malignant infantile osteopetrosis is a rare disease but can be clinically unequivocally diagnosed. Normal bone formation in the presence of decreased bone breakdown leads to the typical symptoms. The only proven curative approach, bone marrow transplantation, can reverse most of the symptoms and prevent progression to irreversible nerve damage when done early in infancy. Therefore, early diagnosis is decisive. We present a case report of an infant with osteopetrosis and discuss pathogenesis and therapeutical options.