Dystrophin-glycoproteins associated in congenital muscular dystrophy: immunohistochemical analysis of 59 Brazilian cases

The congenital muscular dystrophies (CMD) are heterogeneous muscular diseases with early and dystrophic pattern on muscle biopsy. Many diff e rent subtypes have been genetically identified and most phenotypes not yet identified belong to the merosin-positive (MP) CMD subgro u p .Objective: To analyze the immunohistochemical expression of the main proteins of the dystro p h i n - g l y c o p roteins associa- ted complex in muscle biopsy of patients with diff e rent CMD phenotypes, for investigating a possible corre- lation with clinical and histopathological data.Method: Fifty-nine patients with CMD had clinical, histo- pathological and immunohistochemical data evaluated: 32 had MP-CMD, 23 CMD with merosin deficien- cy (MD-CMD), one Ullrich phenotype and three Wa l k e r- Wa r b u rg disease.Results: D y s t rophin and dysfer- lin were normal in all; among the patients with MD-CMD, merosin deficiency was partial in nine who sho- wed the same clinical severity as those with total deficiency; the reduced expression of α- s a rcoglycan (SG) and α- d y s t roglycan (DG) showed statistically significant correlation with severe MD-CMD phenotype.C o n- c l u s i o n :T h e re is a greater relationship between merosin and the former proteins; among MP-CMD patients, no remarkable immunohistochemical/phenotypical correlations were found, although the reduced expre s- sion of β-DG had showed statistically significant correlation with severe phenotype and marked fibro s i s on muscular biopsy.