Hereditary diffuse leukoencephalopathy with axonal spheroids caused by R782H mutation in CSF1R: Case report

We report a biopsy-proven and genetically determined case with leukoencephalopathy showing autosomal dominant inheritance and pre-senile dementia. A 51-year old woman gradually developed a decline in cognitive functions with aphasia and epileptic seizures. Four of her family members were diagnosed as having dementia in their forties to sixties. Five years later she became apathetic and bed-ridden. Brain MRI initially showed fronto-temporal dominant cerebral atrophy with multiple small lacunar-like lesions in the deep white matter, but these white matter lesions became diffuse at an advanced stage. Such possibilities as hereditary vascular or fronto-temporal dementia were clinically suspected, but her family members requested a definitive diagnosis. Brain biopsy showed severe loss of myelin and axons in the white matter with relatively preserved cortical structure. The remaining axons disclosed irregular shapes with the formation of many spheroids, and these findings were consistent with a histopathological diagnosis of neuroaxonal dystrophy. DNA analysis disclosed a novel heterozygous c.2345 G > A (p.782Arg > His) mutation in exon 18 of the colony stimulating factor 1 receptor gene (CSF1R). Hereditary diffuse leukoencephalopathy with axonal spheroids should be included in the differential diagnosis of familial occurrence of pre-senile dementia.