Novel mutation in the mitochondrial transfer RNACys gene in a child

• Author(s): Almeida, L.S. ; Martins, E. ; Santorelli, F.M. ; Vilarinho, L.
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.18/2218
• Origin: Repositório Científico do Instituto Nacional de Saúde
• Subject(s): Doenças Genéticas; Doenças Mitocondriais; Mitochondrial DNA
• Document Type: Conference Object
• Language: English

Description

Mitochondrial DNA (mtDNA) disorders are an important group of genetic diseases presenting with a multifacet array of clinical manifestations. Highly energy-dependent tissues such as central nervous system and skeletal and cardiac muscles are commonly involved either as multisystem or as isolated organ disease. Characteristic symptoms include epilepsy, myopathy, deafness and ophthalmoplegia, all associated with point mutations in the mtDNA. Pathogenic mtDNA mutations can be heteroplasmic or homoplasmic. Heteroplasmic mutations are typically associated with mutations in mt-tRNA genes. Mutations in mt-tRNAs genes are responsible for the majority of the presentations of a mitochondrial disease being associated with marked clinical heterogeneity. Although tRNA-encoding genes make up only 9% of the entire mitochondrial genome, over 40% of all point mutations reported in the mtDNA are located in tRNA genes. Here, we present a child with vomiting episodes and migraine in whom we found a novel variant in the mitochondrial tRNACys gene.