Multiple presentation of mitochondrial disorders

The aim of this study was to assess the heterogeneous clinical presentation s of children with mitochondrial disorders evaluated at a metabolic neuroge netic clinic. The charts of 36 children with highly suspected mitochondrial disorders were reviewed. Thirty one children were diagnosed as having a mi tochondrial disorder, based on a suggestive clinical presentation and at le ast one of the accepted laboratory criteria; however, in five children with no laboratory criteria the diagnosis remained probable. All of the patient s had nervous system involvement. Twenty seven patients also had dysfunctio n of other systems: sensory organs in 15 patients, cardiovascular system in five, gastrointestinal system in 20, urinary system in four, haematopoieti c system in four, and endocrine system in nine. The clinical presentation w as compatible with an established syndrome in only 15 children. Severe lact ic acidosis or ragged red muscle fibres were encountered in very few patien ts. These results suggest that mitochondrial disorders should be evaluated in children presenting with a complex neurological picture or multisystem i nvolvement.