Importance of neurological assessment before bone marrow transplantation for osteopetrosis.

Neurological complications of malignant infantile osteopetrosis are well recognised; successful bone marrow transplantation, when performed early in life, can prevent or halt some of them. In a subgroup of infants osteopetrosis is associated with primary retinal degeneration and/or generalised neurodegeneration. Bone marrow transplantation, in spite of being successful in correcting the osseous and haematological abnormalities, does not influence the progressive course of the neurodegenerative disorder. Thus, the recognition of this subgroup of infants with a very poor prognosis is essential before deciding on bone marrow transplantation.