Journal: European Journal of Paediatric Neurology. 2007 Feb 9; E-publication ahead of print.
Authors and affiliation: van de Glind G, de Vries M, Rodenburg R, Hol F, Smeitink J, Morava E. Department of Pediatrics, Nijmegen Centre for Mitochondrial Disorders, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
The characteristic clinical presentation, especially the appearance of muscle symptoms, is quite unique in children carrying the mtA8344G mutation. The diagnosis of MERRF syndrome is seldom made in the pediatric age. [MERRF syndrome is “one of a group of rare muscular disorders that are called mitochondrial encephalomyopathies.”]
Fatigue is a common finding in children of pubertal age. Fatigue in combination with recurrent resting muscle pain occurs frequently in the initial phase of various hereditary muscle disorders and in several autoimmune, endocrine, and metabolic syndromes.
In the absence of obvious biochemical/metabolic abnormalities and in the lack of neurological symptoms, the complaints are frequently labeled as Fibromyalgia or Chronic Fatigue Syndrome. In patients with behavioral or psychiatric abnormalities, one might even start to question the organic etiology of the complaints.
We describe a family carrying the classic MTTK mutation with a variable degree of heteroplasmy [mix of mutated and unmutated mitochondrial DNA], presenting in childhood as isolated recurrent muscle pain as the first symptom of the disease.