CSF insulin-like growth factor-1 in infantile neuronal ceroid lipofuscinosis

Background: Infantile neuronal ceroid lipofuscinosis (INCL) is a progressive encephalopathy in which the patients are severely disabled by the age of 3 years. It is characterized by cerebral atrophy, selective loss of cortical neurons, and secondary loss of axons and myelin sheaths of the white matter. INCL has been shown to result from a palmitoyl protein thioesterase deficiency. The authors suggested that insulin-like growth hormones and apoptosis might play a role in the pathogenesis of INCL. Methods: The authors measured insulin-like growth factor-1 (IGF-1) and IGF binding protein 3 (IGFBP-3) in the CSF of patients with INCL by radioimmunoassay at an early stage when myelin was starting to diminish. Results: The authors found low CSF IGF-1 but normal IGFBP-3 in patients with INCL compared with control subjects. Also, they observed apoptotic cell death in biopsies of INCL patients. Conclusions: Because the IGF system seems to be important for early brain development, myelination, and neuroprotection, the authors suggest that the pathology in INCL may be associated with low CSF IGF-1.