Propos. - La maladie de Mac Ardle (MMA) ou glycogenose de type V debute le plus souvent dans l'enfance ou l'adolescence. Les symptomes sont generalement suffisamment evocateurs ou les malades suffisamment genes pour que le diagnostic soit porte avant l'age adulte.Methode. - Nous avons etudie de facon retrospective les cas de MMA diagnostiques au service de biochimie de l'hopital Debrousse de Lyon entre 1962-2002, en selectionnant les malades dont le diagnostic a ete porte apres l'age de 30 ans.Resultats. - Nous avons identifies 15 cas repondant a ces criteres et avons pu analyser 11 dossiers. Un douzieme patient (service de medecine interne - Royan) completait la serie. Nous avons analyses les raisons de ce diagnostic tardif : formes debutant tot dans la vie mais peu invalidantes (7 cas), formes debutant apres 20 ans (5 cas dont 3 ayant debute apres 45 ans). Les signes cliniques les plus frequents etaient les manifestations musculaires deficitaires et algiques (8 cas) et le phenomene de second souffle (7 cas). L'elevation de la creatinine phosphokinase etait constante. Le test d'ischemie d'effort, lorsqu'il etait realise (8 cas), etait constamment pathologique (8 cas). L'EMG etait souvent normal (5/11). Plusieurs biopsies musculaires etaient necessaires pour evoquer le diagnostic dans un tiers des cas surtout chez les malades debutant tardivement leur maladie.Conclusion. - Chez un adulte de plus de 30 ans consultant pour une symptomatologie musculaire, si l'interrogatoire retrouve un debut des symptomes avant l'age adulte, on evoquera rapidement une myopathie metabolique dont la MMA. Les formes de MMA debutant tardivement meritent d'etre connues, ce d'autant que leur diagnostic est souvent difficile (biopsies musculaires multiples).
Purpose. - Mc Ardle's disease (MAD) or glycogen storage disease type V, usually starts in childhood or adolescence. Generally diagnosis is made before the early adulthood because patients present well defined syndrome and are constrained.Method. - We retrospectively investigated all MAD cases diagnosed in the biochemical laboratory from Debrousse Hospital in Lyon, during 40 years (1962- 2002). We then selected patients whose diagnosis had been made after 30 years.Results. - Fifteen patients answered our criteria but only 11 files could be analysed. A twelfth patient (service of internal medicine - Royan) supplemented the series. We sought the reasons of a late diagnosis: early age of beginning but few symptoms (7 cases), age of beginning higher than 20 years (5 cases including 3 after 45 years). The principal symptoms were muscular deficit and muscular pains (8 cases) and second wind phenomenon (7 cases). Creatinine phosphokinase level was constantly high. Ischemic effort test when it was carried out was constantly abnormal. Conversely electromyogram was often normal (5 cases). Several biopsies were necessary in a third of the cases to evoke the diagnosis, particularly among the patients with late onset symptoms.Conclusion. - Diagnosis of metabolic MAD is generally easy if the interrogation finds inaugural symptoms in childhood or adolescence even if the patient consults very late in the life. The diagnosis can become much more difficult if it begins late in life (atypical symptoms, need for several muscular biopsy).
