Further evidence for the organisation of the four sarcoglycans proteins within the dystrophin-glycoprotein complex.
Based on the pattern of distribution of the SG proteins in patients with LGMD2C and 2D, and on the observed decreased abundance of dystrophin through WB in some sarcoglycans (SG) patients, we have recently suggested that alpha, beta and delta subunits of sarcoglycan complex might be more closely associated and that gamma-SG might interact more directly with dystrophin. Two additional SG patients here reported give further support to these suggestions: an LGMD2F patient showed patchy labelling for gamma-SG, despite the lack of staining of the other three SG proteins; an LGMD2C boy showed deficiency in dystrophin by means of WB and IF, comparable with an DMD manifesting carrier. These two patients represent further evidence of a closer relation of alpha, beta and delta-SG than of gamma-SG and of the possible association of gamma-SG with dystrophin. In addition the LGMD2C patient illustrates the potential risk of misdiagnosis using only dystrophin analysis, in cases with no positive family history, or when DNA analysis is not informative.
Vainzof
M
M
Departamento de Neurologia, FMUSP, São Paulo, Brazil. mvainzof@usp.br
Moreira
E S
ES
Ferraz
G
G
Passos-Bueno
M R
MR
Marie
S K
SK
Zatz
M
M
D000293:Adolescent; D002648:Child; D003598:Cytoskeletal Proteins / Q000032:analysis*; D049030:Dystroglycans; D016189:Dystrophin / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D049031:Sarcoglycans
D003598:Cytoskeletal Proteins; C483081:DAG1 protein, human; D016189:Dystrophin; D008562:Membrane Glycoproteins; D049031:Sarcoglycans; D049030:Dystroglycans