[McArdle disease: report of four brothers with myophosphorylase deficiency]. / Enfermedad de McArdle: descripción de cuatro hermanos con déficit de miofosforilasa.

Myophosphorylase deficiency, or McArdle disease, is an uncommon entity. The gene for human myophosphorylase has been cloned and is located on chromosome 11, in keeping with the autosomal recessive nature of the disease and there is an excess of male patients. The diagnosis is established by documentation of elevated glycogen content and reduced phosphorylase activity in biopsied muscle tissue. We report four cases with McArdle disease which were 16, 15, 11 and 5 years old. They were brothers, and they came to the hospital because of pain, cramps and myoglobinuria after exercise or infection; in the first case, a male patient, myoglobinuria caused acute renal failure. Three of them showed reduced phosphorylase activity in biopsied muscle tissue. We discuss the different therapeutic possibilities.

[An etiopathogenic and diagnostic update of vasculitis]. / Actualización etiopatogénica y diagnóstica de las vasculitis.

In this study, we examine with attention the latest etiopathogenic findings of this protein-like group of diseases in which even today, exist unclear and controversial aspects. We analyze from an immunological point of view either the role of immunocomplexes and the role of cell-mediated immunity, standing out the direct antibodies-mediated injury, especially emphasizing antineutrophil antibodies. Next, we describe steps and attitudes to be taken when facing one of these diseases diagnosis, including not only suspect, confirmation and degree of spreading, but also setting behaviour guidelines that make feasible the search of associate diseases and discarding other kind of diseases with which may arise some confusion.

Enfermedad de McArdle: descripción de cuatro hermanos con déficit de miofosforilasa / Mcardle disease: report of four brothers with myophosphorylase deficiency

La deficiencia de miofosforilasa o enfermedad de McArdle es una entidad rara. El gen para la enzima miofosforilasa ha sido clonado y localizado en el cromosoma 11. La enfermedad se hereda de forma autosómica recesiva con un predominio en los varones. El diagnóstico se establece por la elevación en el contenido de glucógeno y la reducción de la actividad de la enzima en la biopsia de tejido muscular. Presentamos cuatro hermanos de 16,15,11 y 5 años con enfermedad de Mc Ardle. Consultaron por dolor, calambres y mioglobinuria tras ejercicio o infección, en uno de los casos, la mioglobinuria causó un fallo renal agudo. Tres de los casos demostraron una reducción de la actividad de la fosforilasa en la biopsia muscular. Nosotros comentamos los aspectos diagnósticos y también las diferentes posibilidades terapéuticas. (AU)