RESUMO
We report on a patient with muscle pain not associated with muscle weakness. Microscopic examination of the muscle biopsy revealed rod-like cytoplasmic bodies in many fast fibres. By electron microscopy these had a crystalloid structure identical to the hexagonally cross-linked caveolin 3-positive tubular arrays, previously described in patients with similarly benign myopathy. We found that these inclusions were positive for calsequestrin and for the calsequestrin-binding protein junctin, as well as for caveolin 3. However, the genes coding for these proteins were not mutated. For diagnostic purposes calsequestrin and caveolin 3 positivity should be checked when rods are encountered in muscle biopsy for mild myopathy.
Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Calsequestrina/metabolismo , Proteínas de Membrana/metabolismo , Oxigenases de Função Mista/metabolismo , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Doenças Musculares/patologia , Adulto , Caveolina 3/metabolismo , Humanos , Masculino , Microscopia Eletrônica de Transmissão/métodos , Músculo Esquelético/patologia , Músculo Esquelético/ultraestrutura , Cadeias Pesadas de Miosina/metabolismoRESUMO
Hypoglycosylation of alpha-dystroglycan characterizes a subgroup of muscular dystrophies of variable severity, including Fukuyama congenital muscular dystrophy. We found fukutin gene mutations in a 4.5-year-old Italian patient, with reduced alpha-dystroglycan expression, dystrophic features on muscle biopsy, hypotonia since birth, mild myopathy, but no brain involvement. Mutations in the fukutin gene can be associated with much milder phenotypes than classical Fukuyama congenital muscular dystrophy, and, although rare, can occur in non-Japanese.