A Homoplasmic MT-TV Mutation Associated with Mitochondrial Inheritance of Hereditary Spastic Paraplegia.
Background: Hereditary spastic paraplegia (HSP) is characterized by progressive lower limb weakness and spasticity, with unknown genetic cause in many cases.
Objectives: To identify novel genetic causes of HSP.
Methods: Phenotypic characterization, genetic screening, transcriptome sequencing, and peroneal nerve biopsy were conducted in a Chinese HSP family.
Results: We found a homoplasmic MT-TV (mitochondrial tRNAVal) mutation, m.1661A > G, present in all affected individuals across four generations of a family with complex HSP. Fourth-generation affected individuals displayed earlier onset, likely due to presumptive anticipation, and greater symptom severity, potentially caused by decreased mitochondrial DNA (mtDNA) copy number. Upregulation of mitochondrial autophagy genes in these patients suggested that MT-TV mutations could lead to reduced mtDNA copy number. Neural biopsies revealed ultrastructural abnormalities in myelin and mitochondria.
期刊介绍:
Movement Disorders publishes a variety of content types including Reviews, Viewpoints, Full Length Articles, Historical Reports, Brief Reports, and Letters. The journal considers original manuscripts on topics related to the diagnosis, therapeutics, pharmacology, biochemistry, physiology, etiology, genetics, and epidemiology of movement disorders. Appropriate topics include Parkinsonism, Chorea, Tremors, Dystonia, Myoclonus, Tics, Tardive Dyskinesia, Spasticity, and Ataxia.