FOLATE-DEFICIENCY IN CEREBROSPINAL-FLUID ASSOCIATED WITH A DEFECT IN FOLATE BINDING-PROTEIN IN THE CENTRAL-NERVOUS-SYSTEM

An adult male patient of Dutch ancestry has a slowly progressive neuro logical disease characterised by a cerebellar syndrome, distal spinal muscular atrophy, pyramidal tract dysfunction, and perceptive hearing loss. A severe folate deficiency state was found in CSF in combination with a normal serum and red cell folate state. Two unknown abnormal m etabolites were present in CSF. The concentration of immunoreactive fo late binding protein in CSF was unusually low, whereas the concentrati on of the protein measured with radioligand (H-3-folate) binding was u nusually high. The transfer of folate over the choroid plexus seems to be disturbed, potentially reflecting a defect in the choroid plexus f olate binder.