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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An 11-year-old white female presented with progressive proximal muscle weakness and marked calf hypertrophy. Muscle biopsy showed severe dystrophy with normal expression of dystrophin. There was complete absence of the 50kDa dystrophin-associated glycoprotein (alpha-sarcoglycan). DNA analysis showed novel point mutations (one missense and one splicing) in the alpha-sarcoglycan gene at chromosomal location 17q21, confirming the diagnosis of limb-girdle muscular dystrophy type 2D (LGMD-2D). We believe this is one of the first confirmed white cases of primary alpha-sarcoglycanopathy identified in the UK. This case supports the assumption of a wide geographic prevalence of severe childhood onset autosomal recessive muscular dystrophy and genetic heterogeneity. In the future, with improved diagnostic accuracy it is likely that more cases demonstrating primary or secondary deficiency of alpha-sarcoglycan will be identified. We would recommend staining for dystrophin-associated glycoproteins (sarcoglycans) in all new cases of muscular dystrophy with normal dystrophin, and confirmation with DNA analysis where possible.
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PMID:Absence of alpha-sarcoglycan and novel missense mutations in the alpha-sarcoglycan gene in a young British girl with muscular dystrophy. 939 93

Immunocytochemical deficiency of alpha-sarcoglycan (adhalin) in the skeletal muscle that is associated with normal dystrophin expression has been called adhalinopathy. However, recent molecular biological and genetic studies revealed that alpha-sarcoglycan is one of four subunits of sarcoglycans (alpha-delta) or sarcoglycan complex. Mutations of any one of the genes of these subunits cause loss of sarcoglycan complex, and therefore they are now called sarcoglycanopathy or limb-girdle muscular dystrophy (LGMD) 2C-2F. The frequency of sarcoglycanopathy is about 5-10% of dystrophin-normal muscular dystrophy. Mutation of alpha-sarcoglycan gene is most frequent (34%) among the four sarcoglycan genes as shown in the tables. However, 38% of the patients with sarcoglycanopathy have no mutation, implying the presence of yet unknown sarcoglycan(s) and/or interacting protein(s) with sarcoglycan complex.
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PMID:[The frequency of patients with adhalin deficiency in a muscular dystrophy patient population]. 943 29

Miyoshi distal muscular dystrophy (MDMD) is a young-adult-onset, autosomal recessive inherited dystrophy initially affecting the plantar flexers. We analysed 12 MDMD families, five with consanguineous marriage, for chromosomal linkage using polymorphic microsatellite DNA markers to map MDMD gene. A significant lod score was obtained with the 2p13 locus D2S291 (Zmax = 15.3 at theta = 0). A gene for autosomal recessive limb-girdle muscular dystrophy 2B (LGMD2B) was also mapped 2p13. The onset was in the late teens with weakness and wasting of the pelvic girdle muscles. Now we cannot exclude the possibility that the cause of these diseases are allelic variants in the same gene. YAC contig of the region was constructed. Scleening for muscle genes in the MDMD region is under way.
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PMID:[Miyoshi distal muscular dystrophy]. 943 34

Recent advances in molecular biology have indicated that many mutant animal models of muscular dystrophy share common genetic and protein abnormalities similar to those of the human disease. The best example is a model of Duchenne muscular dystrophy (DMD), the mdx mouse. Similar to dystrophic muscle in DMD patients, dystrophin protein is not expressed along the surface membrane, even though the mdx mouse has no apparent signs of muscular dysfunction. Because clinical and pathologic findings in the dystrophic (mxd) dog are similar to those in DMD patients, it also has been regarded as a good model for therapeutic trials. The best known and most extensively studied dy+dy+ mouse lacks merosin (laminin alpha2), which is one subunit of a basement membrane protein, laminin. Because approximately half of all patients with the classical form of congenital muscular dystrophy also lack merosin, availability of this animal has revived interest in the study of the pathologic mechanism of fiber necrosis resulting from this membrane defect. The dystrophic hamster is a model of limb-girdle muscular dystrophy with sarcoglycan deficiency in which one of the dystrophin-associated glycoproteins, delta-sarcoglycan, is defective. Because these animal models have common protein and genetic defects similar to those seen in people with muscular dystrophies, they have been widely used to examine the effectiveness of gene therapy and the administration of pharmacologic and trophic factors.
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PMID:Animal models of muscular dystrophies. 951 83

Emery-Dreifuss muscular dystrophy is an X-linked neuromuscular disorder caused by defects in the STA gene on Xq28, which codes for a nuclear protein named emerin. Affected patients usually present in early adolescence with scapulo-peroneal muscle weakness and wasting, and contractures of the tendo Achilles, elbows and paraspinal muscles, resulting in spine rigidity. We present here a case of Emery-Dreifuss muscular dystrophy with an unusually severe, early presentation. He presented at 2.5 years with predominantly proximal weakness and mild equinovarus deformity of the right foot. Serum creatine kinase activity was elevated (1994 IU/I) and a muscle biopsy at the age of 4 years showed marked dystrophic abnormalities. Normal expression of dystrophin, and no detectable deletion in the corresponding gene, excluded a diagnosis of Duchenne muscular dystrophy. Similarly, normal expression of alpha-sarcoglycan made a limb-girdle muscular dystrophy caused by a defect in a sarcoglycan unlikely. Several years later, examination of the proband's maternal cousin, aged 14 years, suggested Emery-Dreifuss muscular dystrophy. This was confirmed in both affected boys by the absence of emerin in muscle and leucocytes, and identification of a mutation in exon 4 of the STA gene. Carrier status in both mothers was also confirmed by mutational and protein analysis. Emery-Dreifuss muscular dystrophy should therefore be considered in the differential diagnosis of cases of early onset muscular dystrophy, even in the absence of the typical clinical features.
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PMID:Early presentation of X-linked Emery-Dreifuss muscular dystrophy resembling limb-girdle muscular dystrophy. 960 59

Four types of limb-girdle muscular dystrophy (LGMD) are known to be caused by mutations in distinct sarcoglycan genes. The BIO 14.6 hamster is a model for sarcoglycan-deficient LGMD with a deletion in the delta-sarcoglycan (delta-SG) gene. We investigated the function of the sarcoglycan complex and the feasibility of sarcoglycan gene transfer for LGMD using a recombinant delta-SG adenovirus in the BIO 14.6 hamster. We demonstrate extensive long-term expression of delta-sarcoglycan and rescue of the entire sarcoglycan complex, as well as restored stable association of alpha-dystroglycan with the sarcolemma. Importantly, muscle fibers expressing delta-sarcoglycan lack morphological markers of muscular dystrophy and exhibit restored plasma membrane integrity. In summary, the sarcoglycan complex is requisite for the maintenance of sarcolemmal integrity, and primary mutations in individual sarcoglycan components can be corrected in vivo.
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PMID:Functional rescue of the sarcoglycan complex in the BIO 14.6 hamster using delta-sarcoglycan gene transfer. 966 Sep 67

Miyoshi-type distal muscular dystrophy (MMD) is an autosomal recessively inherited progressive disorder. The putative locus of MMD is linked to the limb-girdle muscular dystrophy 2B locus on chromosome 2p12-14. In this study three of four MMD pedigrees show non-linkage to the region spanned by D2S134-D2S358-D2S145 on chromosome 2p, indicating genetic heterogeneity. A genome wide screen was performed to identify loci linked to MMD. In two non-chromosome 2-linked families, a 23 cM region on chromosome 10 segregated with MMD.
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PMID:Genetic heterogeneity in Miyoshi-type distal muscular dystrophy. 967 85

The limb-girdle muscular dystrophies are a genetically heterogeneous group of inherited progressive muscle disorders that affect mainly the proximal musculature, with evidence for at least three autosomal dominant and eight autosomal recessive loci. The latter mostly involve mutations in genes encoding components of the dystrophin-associated complex; another form is caused by mutations in the gene for the muscle-specific protease calpain 3. Using a positional cloning approach, we have identified the gene for a form of limb-girdle muscular dystrophy that we previously mapped to chromosome 2p13 (LGMD2B). This gene shows no homology to any known mammalian gene, but its predicted product is related to the C. elegans spermatogenesis factor fer-1. We have identified two homozygous frameshift mutations in this gene, resulting in muscular dystrophy of either proximal or distal onset in nine families. The proposed name 'dysferlin' combines the role of the gene in producing muscular dystrophy with its C. elegans homology.
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PMID:A gene related to Caenorhabditis elegans spermatogenesis factor fer-1 is mutated in limb-girdle muscular dystrophy type 2B. 973 27

Limb-girdle muscular dystrophy type 2D (LGMD 2D) is an autosomal recessive disorder caused by mutations in the alpha-sarcoglycan gene. To determine how alpha-sarcoglycan deficiency leads to muscle fiber degeneration, we generated and analyzed alpha-sarcoglycan- deficient mice. Sgca-null mice developed progressive muscular dystrophy and, in contrast to other animal models for muscular dystrophy, showed ongoing muscle necrosis with age, a hallmark of the human disease. Sgca-null mice also revealed loss of sarcolemmal integrity, elevated serum levels of muscle enzymes, increased muscle masses, and changes in the generation of absolute force. Molecular analysis of Sgca-null mice demonstrated that the absence of alpha-sarcoglycan resulted in the complete loss of the sarcoglycan complex, sarcospan, and a disruption of alpha-dystroglycan association with membranes. In contrast, no change in the expression of epsilon-sarcoglycan (alpha-sarcoglycan homologue) was observed. Recombinant alpha-sarcoglycan adenovirus injection into Sgca-deficient muscles restored the sarcoglycan complex and sarcospan to the membrane. We propose that the sarcoglycan-sarcospan complex is requisite for stable association of alpha-dystroglycan with the sarcolemma. The Sgca-deficient mice will be a valuable model for elucidating the pathogenesis of sarcoglycan deficient limb-girdle muscular dystrophies and for the development of therapeutic strategies for this disease.
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PMID:Progressive muscular dystrophy in alpha-sarcoglycan-deficient mice. 974 77

Limb-girdle muscular dystrophy type 2C (LGMD2C) is an autosomal recessive muscular dystrophy with primary gamma-sarcoglycan deficiency, generally associated with a severe clinical course. gamma-sarcoglycan, a 35kDa dystrophin-associated protein, is encoded by a single gene on chromosome 13q12. Six different mutations have been described in that gene, and it has been proved they are the origin of the disease. One of these mutations (C283Y), a G-->A transition in codon 283, was recently and exclusively identified in Gypsy patients from different European countries. We report the study of 11 LGMD2C unrelated Gypsy families (nine Spanish and two Portugese). The muscle biopsies of these patients showed a drastically decreased immunostaining with alpha and gamma-sarcoglycan antibodies. All the patients were homozygous for C283Y missense mutation, and all affected chromosomes (patients and heterozygous relatives) carried the allele 5 (112 bp) of the intragenic microsatellite D13S232. Unexpectedly, this allele is most frequent in the Caucasian population but not in the normal Gypsy population. The clinical severity of all patients demonstrates that the C283Y missense mutation in a homozygous state causes a severe LGMD2C (DMD-like). The elevated number of families ascertained let us assume that LGMD2C is prevalent in the Gypsy population, and that all the families have inherited a founding mutation.
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PMID:Severe limb girdle muscular dystrophy in Spanish gypsies: further evidence for a founder mutation in the gamma-sarcoglycan gene. 978 Oct 48


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