Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dystrophin is a large cytoskeletal protein encoded by the Duchenne muscular dystrophy (DMD) gene. Dystrophin is associated with a large oligomeric complex of sarcolemmal glycoproteins, including the novel laminin-binding glycoprotein called dystroglycan, which provides a linkage to the extracellular matrix. In DMD, the absence of dystrophin leads to a drastic reduction in all of the dystrophin-associated proteins. In severe childhood autosomal recessive muscular dystrophy with DMD-like phenotype (SCARMD), a specific deficiency of the 50 kDa dystrophin-associated glycoprotein is found. Thus, the disruption/dysfunction of the dystrophin-glycoprotein complex due to the deficiency of one or more of the dystrophin-associated proteins is presumed to cause the disruption of the linkage between the subsarcolemmal cytoskeleton and the extracellular matrix. This may render muscle cells susceptible to necrosis in two forms of severe childhood muscular dystrophy, DMD and SCARMD.
 ...
PMID:Deficiency of dystrophin-associated proteins: a common mechanism leading to muscle cell necrosis in severe childhood muscular dystrophies. 835 36

Recent molecular and biochemical studies have disclosed the detailed molecular organization of the dystrophin-glycoprotein complex, which links the cytoskeleton to the extracellular matrix. Defects in several components of this complex cause different types of muscular dystrophy. This glycoprotein complex is also involved in clustering and anchoring acetylcholine receptors at the postsynaptic membrane.
 ...
PMID:Dystrophin-glycoprotein complex: molecular organization and critical roles in skeletal muscle. 854 44

Muscular dystrophies primarily affect skeletal muscle and are characterized by progressive muscle wasting and weakness. Although these diseases have been clinically recognized for some time, genetic defects in a number of muscular dystrophies only recently have been identified. One of the most important advances in understanding the molecular genetics of neuromuscular diseases has been the cloning of the gene encoding dystrophin, the protein that is absent in the muscle of patients with Duchenne and Becker muscular dystrophy. Several dystrophin-associated proteins have been identified. Components of the dystrophin-glycoprotein complex are being characterized, and evidence indicates that proteins of this complex may be responsible for other forms of muscular dystrophy.
 ...
PMID:Dystrophinopathies and related disorders. 857 67

The clinical, biochemical and histochemical features of 14 patients (nine females and five males) with severe childhood autosomal recessive muscular dystrophy (SCARMD) seen at a tertiary hospital in Riyadh from 1982 to 1993 are described. Onset was at 3 to 9 (median 3) years and four of five children aged > 12 years lost ambulation. Five of the eight pairs of parents were closely consanguineous. The mean creatine kinase was 20 times the upper normal limit. Histochemistry of muscle showed dystrophic features in all cases, and dystrophin was positive in all cases examined (N = 6). Three patients (two girls and a boy) were deficient in adhalin, the 50-kDa dystorphin-associated glycoprotein. A boy aged 13 years had rapidly progressing disease. Another boy of the same age (from a family characterized by early onset and slower progression) had normal dystrophin and adhalin. The clinical features conformed with previous observations from Sudan, North Africa and Qatar in the Arabian Peninsula. The disease is common in Saudi Arabia and seems to be more prevalent than Duchenne muscular dystrophy.
 ...
PMID:Clinical and molecular pathological features of severe childhood autosomal recessive muscular dystrophy in Saudi Arabia. 863 23

We have partially sequenced rabbit skeletal muscle gamma-sarcoglycan, an integral component of the dystrophin-glycoprotein complex. Specific antibodies were produced against a gamma-sarcoglycan peptide and used to examine the expression of gamma-sarcoglycan in skeletal muscle of patients with severe childhood autosomal muscular dystrophy linked to chromosome 13q12 (SCARMD). We show by immunofluorescence and Western blotting that in skeletal muscle from these patients gamma-sarcoglycan is completely absent and alpha- and beta-sarcoglycan are greatly reduced in abundance, whereas other components of the DGC are preserved. In addition, we show that in normal muscle alpha-, beta-, and gamma-sarcoglycan constitute a tightly associated sarcolemma complex which cannot be disrupted by SDS treatment.
 ...
PMID:Absence of gamma-sarcoglycan (35 DAG) in autosomal recessive muscular dystrophy linked to chromosome 13q12. 864 26

Dystrophin is associated with several novel sarcolemmal proteins via the cysteine-rich/C-terminal domains. The dystrophin-associated proteins are classified into three groups: (1) alpha- and beta-dystroglycan, (2) adhalin, 35DAG and A3b, and (3) members of the syntrophin family. Dystrophin interacts with F-actin via the N-terminal domain. Alpha-dystroglycan binds laminin-2, a major component of the basal lamina. These findings indicate that the dystrophin-glycoprotein complex (DGC) links the subsarcolemmal cytoskeleton with the basal lamina, thus providing mechanical stability to the sarcolemmal. The DGC may also play a role in signal transduction. We have reported previously the deficiency of adhalin in skeletal muscle of Arab patients afflicted with severe childhood autosomal recessive muscular dystrophy (SCARMD). SCARMD is now known to affect other races including Europeans and Japanese. Although the phenotype of this disease can mimic Duchenne muscular dystrophy in severe cases, it is sometimes quite mild. SCARMD is genetically heterogeneous. Recently, adhalin gene mutations have been demonstrated in European, Arab and Japanese families with SCARMD. Another locus is on chromosome 13q, however, the mutated gene remains elusive. In the advanced stages of SCARMD, the expression of laminin is disturbed, suggesting that adhalin deficiency may cause the dysfunction of the DGC as a laminin receptor, which may eventually lead to muscle cell death.
 ...
PMID:[Severe childhood autosomal recessive muscular dystrophy]. 875 17

The spectacular progress concerning dystrophin and its pathology, the dystrophinopathies, has led to a somewhat arbitrarily separated heterogeneous group of nondystrophinopathic muscular dystrophies that currently comprise the Emery-Dreifuss type, the nosologically heterogeneous autosomal-recessive limb-girdle muscular dystrophy, the severe childhood autosomal-recessive muscular dystrophy, the merosin-positive and -negative congenital muscular dystrophies, the autosomal-recessive distal muscular dystrophy of Miyoshi, the facio-scapulo-humeral muscular dystrophy, and myotonic dystrophy, both the adult and neonatal variants. Deficiencies of adhalin in a particular form of limb-girdle muscular dystrophy, and of merosin in a particular form of congenital muscular dystrophy as well as the newly discovered principle of abnormal tri-nucleotide repeats in myotonic dystrophy are evidence of progress that has also amplified the notion of the dystrophinopathies that the protein-deficient muscular dystrophies can now be considered examples of contributions of the dystrophin-glycoprotein complex across the muscle fiber plasma membrane.
 ...
PMID:Nondystrophinopathic muscular dystrophies including myotonic dystrophy. 879 45

Mutations in any of the genes encoding the alpha, beta or gamma-sarcoglycan components of dystrophin-associated glycoproteins result in both sporadic and familial cases of either limb-girdle muscular dystrophy or severe childhood autosomal recessive muscular dystrophy. The collective name 'sarcoglycanopathies' has been proposed for these forms. We report the identification of a fourth member of the human sarcoglycan family. We named this novel cDNA delta-sarcoglycan. Its mRNA expression is abundant in striated and smooth muscles, with a main 8 kb transcript, encoding a predicted basic transmembrane glycoprotein of 290 amino acids. Antibodies specifically raised against this protein recognized a single band at 35 kDa on western blots of human and mouse muscle. Immunohistochemical staining revealed a unique sarcolemmal localization. FISH, radiation hybrid and YAC mapping concordantly linked the delta-sarcoglycan gene to 5q33, close to D5S487 and D5S1439. The gene spans at least 100 kb and is composed of eight exons. The identification of a novel sarcoglycan component modifies the current model of the dystrophin-glycoprotein complex.
 ...
PMID:Identification of a novel sarcoglycan gene at 5q33 encoding a sarcolemmal 35 kDa glycoprotein. 884 38

Malignant limb-girdle muscular dystrophy (MLGMD) was proposed by Miyoshi et al. in 1966 as a clinical and genetic entity of muscular dystrophy, with clinical features similar to Duchenne muscular dystrophy but showing autosomal recessive inheritance. Recently, deficiency of alpha-sarcoglycan (adhalin), which is one of the components of dystrophin-glycoprotein complex, in the skeletal muscle has been found in several patients with MLGMD or severe childhood autosomal recessive muscular dystrophy. To investigate alpha-sarcoglycan gene mutations in patients with MLGMD, we analyzed cDNA prepared from skeletal muscle by reverse transcription polymerase chain reaction (RT-PCR), or genomic DNA prepared from peripheral blood leukocytes by PCR, using single-strand conformation polymorphism (SSCP). When products amplified by RT-PCR or PCR showed aberrant conformers on SSCP analysis, these products were sequenced by the fluorescence-based dideoxy termination method. We found missense mutations, insertions or deletions in the alpha-sarcoglycan gene in 6 families with MLGMD. In the literature, alpha-sarcoglycan gene mutations have been identified in 21 families with MLGMD/SCARMD including our 6 families. Half of the families have the cytosine to thymidine substitution at nt.229, resulting in the replacement of Arg by Cys at codon 77, and most of the mutations have been found in the region coding extracellular domain of alpha-sarcoglycan. Analysis of the alpha-sarcoglycan gene is indispensable for diagnosis, assessment of prognosis, genetic counseling, and future gene therapy in patients with autosomal recessive childhood-onset muscular dystrophy.
 ...
PMID:[Gene analysis in patients with muscular dystrophy: alpha-sarcoglycan (adhalin) gene mutations in patients with malignant limb-girdle muscular dystrophy]. 912 Sep 97

Efforts to understand the function of dystrophin, the protein product for the Duchenne muscular dystrophy gene, resulted in the purification of the dystrophin-glycoprotein complex. Over the past year several novel components of this complex have been identified. Recent studies have extended the number of muscular dystrophies associated with the oligomeric complex to six genetically distinct diseases, including three new forms of limb-girdle muscular dystrophy and one form of congenital muscular dystrophy.
 ...
PMID:Muscular dystrophies and the dystrophin-glycoprotein complex. 914 99


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>