[P3-153] A case of spinocerebellar degeneration with KIF1A de novo mutation
[Introduction] Spinocerebellar degeneration (SCD) is a relatively rare disease in early childhood. Its underlying pathophysiological mechanism has been studied with molecular biological technique for last 20 years, and many responsible genetic candidates has been proposed and classified. KIF1A is a newly reported neuron-specific motor protein and has KIF1A gene is strongly related to cerebellar atrophy. We report a SCD case of 8-years-old girl with KIF1A mutation. [Case] 16-month-old girl visited to the neurological department of outpatient division of our hospital, suffering from hypotonia of extremities and developmental delay. She could sit, but could not crawl, climb up, or speak. After careful neurological examination, the only abnormal finding was hypotonia, Neuroimaging and neroelectrical investigations did not show any abnormal findings, and only mild rises in AST and CK levels in her serum were positive findings. With physiotherapy, her motor activities improved. However, ataxic gait and mental retardation became prominent with aging. Brain MRI study, performed at the age of 8, revealed spherical as well as vermian cerebellar atropy, and we identified KIF1A de novo mutation by the exome sequencing. [Discussion] Several clinical symptoms have been reported as the characteristics of KIF1A mutations. Of such symptoms, mental retardation, ataxia, and atrophic changes of optic discs and cerebellar atrophy were common with previously reported ones. However, other symptoms previously reported, such as microcephaly, epilepsy, spastic paralysis and cerebral atrophy were not observed in the present case.