Phenotype and sarcoglycan expression in Tunisian LGMD 2C patients sharing the same del521-T mutation.
Limb-girdle muscular dystrophy type 2C is an autosomal recessive muscular disorder caused by mutations in the gene encoding the gamma-sarcoglycan subunit. This gamma-sarcoglycanopathy is prevalent in Tunisia where only one homozygous mutation a 521-T deletion has been identified. The aim of this study was to carry out a comparative clinical and immunocytochemical analysis of Tunisian patients sharing the same gamma-sarcoglycan gene mutation. One hundred and thirty-two patients were classified as severe, moderate or mild according to a calculated severity score. Heterogeneous phenotypes between siblings were encountered in 75% of the families. The severity of the disease was not found to be related to the age of onset. Immunohistochemical studies of muscle biopsy showed a total absence of gamma-sarcoglycan, a normal or slightly reduced alpha and delta-sarcoglycans whereas the expression of beta-sarcoglycan was variable. The residual sarcoglycan expression was not related to the clinical phenotype. In conclusion, the phenotypic variability in sarcoglycanopathies in Tunisia seems to involve a modifying gene controlling the course of the disease.
Kefi
M
M
Institut National de Neurologie, Laboratoire de Neurobiologie Moléculaire, 1007 La Rabta, Tunis, Tunisia.
Amouri
R
R
Driss
A
A
Ben Hamida
C
C
Ben Hamida
M
M
Kunkel
L M
LM
Hentati
F
F
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003598:Cytoskeletal Proteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D004252:DNA Mutational Analysis; D049030:Dystroglycans; D004777:Environment; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics; D005820:Genetic Testing; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008562:Membrane Glycoproteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D009136:Muscular Dystrophies / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D049031:Sarcoglycans; D014416:Tunisia
D003598:Cytoskeletal Proteins; C483081:DAG1 protein, human; D008562:Membrane Glycoproteins; D049031:Sarcoglycans; D049030:Dystroglycans