DEFICIT DI CARNITINA-PALMITOIL TRANSFERASI (CPT) IN DUE CASI DI MIOPATIA MITOCONDRIALE DA DIFETTO DEL COMPLESSO 1

Carnitine-Palmitoyl-Transferase (CPT) deficiency is a rare condition originally reported by Di Mauro in 1973, affecting only skeletal muscle clinically in most patients. We reported the biochemical data from 18 patients suffering from mitochondrial myopathies (deficiencies localized to complex 1,3,4-single or multiple-) with different clinical expression (ranging from fratigable limb weakness to dementia) to evaluate the possibility of a related CPT deficiency. In fact, in a previous paper published in 1987 by Carey, a single case was reported whose history and muscle biopsy findings were those of a mitochondrial myopathy but who had an associated CPT deficiency. In two patients (49 years old man and 38 years old woman) we reported a significative deficiency by CPT activity. Both patients clinically presented the same features (fatiguable limb weakness, no clinical or laboratory evidence of central nervous system, cardiac or retinal involvement) and were biochemically diagnosed as Complex 1 deficiency (50% activity). Carnitine assay was normal and muscular biopsy revealed several ragged-red fibers with the Gomori Trichrome stain and no excess of intrafibrillary lipid with the Sudan Black stain. We reported two patients with several data suggestive for a mitochondrial myopathy with an associated CPT deficiency, a condition which normally has completely different clinical and morphological features. With biochemical tests we confirm the suggestion that CPT deficiency could be caused by a mutant enzyme with different affinity for substrate concentration.