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

We describe a unique six-generation, highly consanguineous family originating from an isolated mountainous village in the Russian province of Daghestan. Three separate clinical phenotypes of progressive muscular dystrophy were identified in this large family. Seven patients developed a classical limb-girdle variant of muscular dystrophy (LGMD), with disease onset at 15-30 years and loss of ambulation within a 25-year course. The second group included three patients with a slowly progressive distal myopathy first manifested in the late teens and confined to the tibial and calf muscles. Each of these two phenotypes segregated independently as an autosomal recessive trait, and muscle biopsies showed non-specific myopathic changes. Lastly, two male siblings exhibited an atypical variant of Duchenne muscular dystrophy confirmed by detection of a deletion in the dystrophin gene. To clarify the molecular basis of the polymorphic autosomal recessive form of muscular dystrophy in this kindred, we performed molecular genetic studies on 67 family members and obtained significant evidence for linkage to chromosome 2p. A maximum pairwise lod (logarithm of odds) score of 5.64 was achieved at the zero recombination fraction (i.e. at theta = 0.00) for locus D2S291; multipoint linkage analysis confirmed the most likely location of a mutant gene near D2S291. The patients with LGMD and those with the distal muscular dystrophy phenotype share a common affected homozygous haplotype associated with the same founder chromosome; key recombinants defined D2S286 and D2S292 to be the closest loci flanking the mutant gene. Remarkably, two clinically distinct forms of autosomal recessive muscular dystrophy, LGMD type 2B (LGMD2B) and Miyoshi myopathy, were recently mapped to the same locus. We suggest that all three chromosome 2p-linked conditions may represent allelic disorders, i.e. different phenotypic expressions of a single gene.
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PMID:Clinical and molecular analysis of a large family with three distinct phenotypes of progressive muscular dystrophy. 900 96

DNA analysis of peripheral blood leucocytes is routinely used to demonstrate mutations in the dystrophin gene in patients with Duchenne's muscular dystrophy. In approximately 35% of patients. DNA studies are not informative; in these patients immunochemical analysis of a muscle-biopsy specimen can determine whether dystrophin, the protein product of the gene for Duchenne's dystrophy, is absent. DNA analysis can be performed in amniocytes for the prenatal diagnosis; immunochemical testing for dystrophin cannot be performed because the protein is not expressed in these cells. To circumvent this limitation in prenatal diagnosis, we induced myogenesis in amniocyte cultures by addition of a rhabdomyosarcoma's cell line supernatant. Rhabdomyosarcomas are tumors of skeletal muscle and known to produce myogenic factors. After 6 weeks skeletal-muscle proteins could be detected in 10 amniocyte cultures. Cultures from fetuses with no family history of Duchenne's dystrophy expressed dystrophin, cultures from patients with Duchenne's dystrophy were dystrophin-deficient. Immunochemical analysis of dystrophin in genetically altered non-muscle cells may be applicable to the prenatal diagnosis of Duchenne's muscular dystrophy when conventional DNA analysis is not informative.
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PMID:[In vitro transformation of amniotic cells to muscle cells--background and outlook]. 901 20

The molecular basis of two allelic forms of muscular dystrophy, Duchenne (DMD) and Becker (BMD), has been explained by frame shift hypothesis. In order to test this hypothesis, deletional mutations in 59 patients confirmed to have DMD and 11 BMD patients were analysed using multiplex polymerase chain reaction and Southern hybridization with dystrophin cDNA probes. Translational reading frame of the dystrophin gene was derived from 'Border type' analysis of exons flanking the intragenic deletions. The correlation between genotype (reading frame) and phenotype (clinical severity) showed higher number of DMD patients (approximately 20%) deviating from the frame shift hypothesis. The patients who deviated had deletions at the central hot spot region of the dystrophin gene. The presence of these deviations in a large number of DMD patients highlights the difficulties in predicting the clinical progression of the disease based only on DNA profile.
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PMID:Genotype-phenotype correlation in Duchenne/Becker muscular dystrophy patients seen at Lucknow. 902 33

Population-based variations in frequency and distribution of dystrophin gene deletions have been recognized in Duchenne/Becker (DMD/BMD) muscular dystrophy patients. In the present study, DNA samples from 121 unrelated DMD/BMD patients from North India were analyzed for deletional studies with multiplex PCR and Southern hybridization. A total of 88 (73%) patients showed intragenic deletions in the dystrophin gene. The observed proportion of gene deletions is relatively high, particularly compared with that of Asian counterparts. However, the distribution of breakpoints across the gene does not show significant variations.
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PMID:Proportion and pattern of dystrophin gene deletions in north Indian Duchenne and Becker muscular dystrophy patients. 904 22

The deletion spectrum of the dystrophin gene was studied in 25 patients with Duchenne's muscular dystrophy (DMD) from 23 families in Tajikistan. To detect deletions, 17 various regions of the dystrophin gene were amplified by means of polymerase chain reaction (PCR). Deletions were revealed in 13 patients from 12 families (52%). The deletion frequency differed in different gene exons, but deletions in the distal part of the gene prevailed (in 91% of cases). Deletions from exons 47 and 48 were detected in 22% of patients; deletions from exon 50 were detected in 35% of patients (73% of patients with deletions). This showed the significance of analyzing the distal part of the gene for DMD diagnostics in Tajikistan. Studying the location of deletion breakpoints revealed a "hot spot" within the dystrophin gene: right (distal) deletion breakpoints occurred between exons 50 and 52 in 73% of deletions.
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PMID:[Deletion analysis of the dystrophin gene in patients with Duchenne's muscular dystrophy in Tajikistan]. 909 12

A 4-year-old girl was referred for evaluation for a mild but persistent serum aspartate aminotransferase (AST) elevation detected incidentally during routine blood screening for a skin infection. Serum creatine kinase activity was found to be increased. Immunohistochemical study for dystrophin in her muscle biopsy showed results consistent with a carrier state for muscular dystrophy. Molecular work-up showed the proposita to be a carrier of a deletion mutation of exon 48 of the dystrophin gene. Four male relatives also had the deletion mutation, yet showed no clinical symptoms of muscular dystrophy (age range 8-58 yrs). Linkage analysis of the dystrophin gene in the family showed a spontaneous change of an STR45 allele, which could be due to either an intragenic double recombination event, or CA repeat length mutation leading to identical size alleles. To our knowledge, this is the first documentation of an asymptomatic dystrophinopathy in multiple males of advanced age. Based on molecular findings, this family would be given a diagnosis of Becker muscular dystrophy. This diagnosis implies the development of clinical symptoms, even though this family is clearly asymptomatic. This report underscores the caution which must be exercized when giving presymptomatic diagnoses based on molecular studies.
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PMID:Asymptomatic dystrophinopathy. 909 54

The main goal of this study was to determine and characterise the types of mutations in two monogenic human disorders: cystic fibrosis (CF) and Duchenne/Becker muscular dystrophy (DMD, BMD) and the susceptibility allele frequency in a polygenic disease: type I insulin-dependent diabetes mellitus (IDDM). After analysing 220 chromosomes for mutations in the CF (Cystic Fibrosis Transmembrane Conductance Regulator = CFTR) gene, delta F508 mutation was most abundant (41%) and out of the non-delta F508 CF mutations 5% was identified as G542X, G551D, R553X, N1303K and W1282X. The CF haplotype analysis by using linked markers to the CFTR gene revealed that the CF "B" haplotype occurred in 66.7% of patients, and this haplotype was 57.2% in patients carrying the delta F508 mutation. Prenatal genetic diagnosis for CF was performed in 10 fetuses: 3 were affected, 6 were carriers, and 1 without any CF mutation. Fifty % of 66 patients with DMB/BMD muscular dystrophy had one or more exon deletions in the dystrophin gene. Eighty-five % of the deletions occurred at the 3' and 15% at the 5' end of the gene. Out of the three prenatal diagnosis in one case DMD was substantiated. Thirty-six % of 50 patients with IDDM possessed four, 44% three and 20% two susceptibility markers in the HLA-DQA1, -DQB1 region. The onset of the disease correlated with the number of susceptibility alleles.
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PMID:Molecular genetic studies in monogenic and polygenic human diseases. 919 7

To clarify new mutational rates in the dystrophin gene between deletion and duplication mutations, carrier diagnosis was performed on 123 mothers of probands suffered from Duchenne (DMD) and Becker (BMD) muscular dystrophy. Quantitative Southern blot analysis with cDNA probes was applied in this study. Out of 108 mothers of DMD/BMD patients with deletion mutation in dystrophin gene, 69 were carriers and 39 were non-carriers. On the other hands, all of 15 mothers of probands with duplication mutation were carriers. The fact that no new mutation occurred in oogenesis in the families with duplication mutations in dystrophin gene indicates that duplications arise in spermatogenesis. The risk of the mother of an isolated case of DMD/BMD with duplication mutation of being a carrier is significantly higher than the estimated risk based on the equality of new mutation in oogenesis and spermatogenesis.
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PMID:[Difference of new mutation rates in dystrophin gene between deletion and duplication mutation in Duchenne and Becker muscular dystrophy]. 921 19

Golden retriever muscular dystrophy (GRMD) is an excellent model for the study of the efficacy of gene therapy in dystrophin deficient myopathies for there are many similarities between affected dogs and Duchenne muscular dystrophy (DMD) in boys. GRMD is not caused by deletion mutation but results from a point mutation in the consensus splice acceptor in intron 6 of the canine dystrophin gene. As a result exon 7 is skipped during processing of the GRMD dystrophin messenger RNA. We have developed a rapid test which makes direct use of exon 7 specific genomic PCR products. We have undertaken preliminary experiments on gene therapy using the mini-gene and the full length gene alone and in combination with lipofectin and/or the bacterial beta-galactosidase reporter gene Lac Z. Following direct injection of the Lac Z plasmid, either alone or with lipofectin, about 50% of the sites showed expression when biopsied some 14 days later. The beta-galactosidase activity was present in muscle and granulation tissue but was never abundant. Pups injected intraperitoneally with Lac Z were found to have positive material in their mesenteric lymph nodes, liver and spleen. Those injected with Lac Z and lipofectin also had positive material in the diaphragm, intercostal muscles and abdominal muscles, but again only a small amount of positive material was present at any of the sites. In animals directly injected into the muscle with the dystrophin mini-gene, half had positive staining for dystrophin in biopsies taken 14 days later. Of the 6 sites in the muscles of animals given the mini-gene and lipofectin only one had fibres positive for dystrophin when examined 14 days later. Six pups were injected directly with full-length gene construct and when biopsies were taken 10 days later two of the animals had strongly stained peripheries to a small number of fibres.
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PMID:Use of the dog model for Duchenne muscular dystrophy in gene therapy trials. 926 46

Primary deficiency of merosin is the cause of the classic form of congenital muscular dystrophy (CMD) accompanied by brain white matter abnormalities. We report a female infant with dystrophinopathy who was deficient in merosin in skeletal muscle. The patient had a phenotype of typical CMD and white matter abnormalities on brain MRI. Merosin was greatly reduced in the biopsied skeletal muscle. However, the expression of dystroglycan and syntrophin was also greatly reduced, and the immunoreactivity for the antibodies against the cysteine-rich/C-terminal domains of dystrophin was absent in the sarcolemma. Reverse transcriptase polymerase chain reaction analysis of the dystrophin gene revealed a complete lack of exons 71 through 74. In skeletal muscle, only the mutant gene was expressed. These results suggest that the patient is a symptomatic Duchenne muscular dystrophy carrier with skewed X-inactivation. This patient illustrates for the first time that a dystrophin abnormality can cause a secondary deficiency of merosin in dystrophinopathy. The reduction of merosin may account for the clinical phenotype of CMD and correlate with the white matter abnormalities in our patient.
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PMID:Deficiency of syntrophin, dystroglycan, and merosin in a female infant with a congenital muscular dystrophy phenotype lacking cysteine-rich and C-terminal domains of dystrophin. 927 Jun


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