[Muscular dystrophy due to a deficit of gamma-sarcoglycan. A report of three patients with the Delta-521t mutation].
BACKGROUND
gamma-sarcoglicanopathies, also classified as limb girdle muscular dystrophy type 2C (LGMD2C) are a group of autosomal recessive muscular dystrophies due to mutations in 13q12 and subsequent g sarcoglican deficiency. The protein is one of the components of the dystrophin associated glycoprotein complex and is thought to impart structural integrity to the myofibre. The clinical course of the disease may be heterogeneous, ranging from severe forms with onset in the first decade and rapid progression resembling Progressive Duchenne muscular dystrophy (DMD) to milder forms with later onset and slower course. Cases hitherto reported in Spain corresponds to gypsie patients, homozygous for C283Y missense mutation.


METHODS
Here, we report three new galician (Northwest Spain) patients (one male and one female sibling cases) with a severe DMD like muscular dystrophy homozygous for D 521T. In the first male familial case, initial diagnosis of DMD was made. On reevaluation fourteen years later, inmunohistochemical and molecular studies allowed for a definitive g sarcoglicanopathy diagnosis.


CONCLUSIONS
Patients with a primary sarcoglycanopathy may be clinically indistinguishable from those with the primary dystrophinopathies. Probably, the diagnosis of LGMD are underestimated and a number of male patients diagnosed as DMD really corresponds to a recessive form o muscular dystrophy. Consequently, a definitive diagnosis rests on appropriate inmunohistochemical and molecular analysis, specially in those patients showing a normal pattern of dystrophin and/or suggestive for an autosomal recessive mode of inheritance.
Eirís-Puñal
J
J
Servicio de Neuropediatría, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, 15705, España. jmeiris@wanadoo.es
Pintos-Martínez
E
E
Lasa
A
A
Gallano
P
P
Castro-Gago
M
M
D000293:Adolescent; D000328:Adult; D002648:Child; D003598:Cytoskeletal Proteins / Q000172:deficiency* / Q000235:genetics*; D016189:Dystrophin / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000172:deficiency* / Q000235:genetics*; D018482:Muscle, Skeletal / Q000473:pathology; D009136:Muscular Dystrophies / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D049031:Sarcoglycans; D013030:Spain
D003598:Cytoskeletal Proteins; D016189:Dystrophin; D008562:Membrane Glycoproteins; D049031:Sarcoglycans