A new CSF1R mutation presenting with an extensive white matter lesion mimicking primary progressive multiple sclerosis.

HDLS (Hereditary Diffuse Leukodystrophy with Spheroids) is a hereditary leukodystrophy whose main clinical manifestations include parkinsonism, spasticity, and ataxia. Genetic defects in the colony-stimulating factor 1 receptor (CSF1R) gene have been reported in many HDLS cases. The present report describes a new missense mutation Arg777Gln involving exon 18 of the CSF1R gene in a sporadic patient presenting with tumor-like lesions mimicking primary progressive multiple sclerosis. The patient was initially diagnosed with a progressive variant of multiple sclerosis and received inadequate treatments. Although most HDLS cases have a positive family history, this disease should also be suspected in sporadic patients showing unusual white matter lesions at MRI.