Movement disorders in genetically confirmed mitochondrial disease and the putative role of the cerebellum.

Background: Mitochondrial disease can present as a movement disorder. Data on this entity's epidemiology, genetics, and underlying pathophysiology, however, is scarce.

Objective: The objective of this study was to describe the clinical, genetic, and volumetric imaging data from patients with mitochondrial disease who presented with movement disorders.

Parental origin and functional relevance of a de novo UBE3A variant.

Sequence analysis of the imprinted UBE3A gene in a 3-year-old girl suspected of having Angelman syndrome had revealed a de novo 3bp in frame deletion predicted to encode a protein lacking the amino acid G538 (based on sequence NM_130838). In order to assess the clinical relevance of this unknown variant, we determined the parental origin and the functional consequences of the deletion. We separated the two chromosomes 15 by microdissection of metaphase spreads and used cytogenetic and molecular markers to demonstrate that the deletion is on the maternal chromosome.