A novel de novo STXBP1 mutation is associated with mitochondrial complex I deficiency and late-onset juvenile-onset parkinsonism.

Research paper by Michael J MJ Keogh, D D Daud, A A Pyle, J J Duff, H H Griffin, L L He, C L CL Alston, H H Steele, S S Taggart, A P AP Basu, R W RW Taylor, R R Horvath, V V Ramesh, Patrick F PF Chinnery

Indexed on: 25 Nov '14Published on: 25 Nov '14Published in: neurogenetics


Mutations in STXBP1 have recently been identified as a cause of infantile epileptic encephalopathy. The underlying mechanism of the disorder remains unclear and, recently, several case reports have described broad and progressive neurological phenotypes in addition to early-onset epilepsy. Herein, we describe a patient with early-onset epilepsy who subsequently developed a progressive neurological phenotype including parkinsonism in her early teens. A de novo mutation in STXBP1 (c.416C>T, p.(Pro139Leu)) was detected with exome sequencing together with profound impairment of complex I of the mitochondrial respiratory chain on muscle biopsy. These findings implicate a secondary impairment of mitochondrial function in the progressive nature of the disease phenotype.