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

DMD and BMD are now understood at the genetic, biochemical, and molecular levels. At the genetic level, both disorders result from mutations of the X-linked gene encoding dystrophin. At the biochemical level, DMD results from the deficiency of a large protein called dystrophin, whereas BMD results when dystrophin is present, though abnormal in either amount or molecular structure. To date, thousands of patients have been analyzed for mutations of the dystrophin gene in peripheral blood DNA or alterations of the dystrophin protein in muscle tissue. The severity of the clinical phenotype of these patients has been compared with their dystrophin gene mutations and corresponding dystrophin protein alterations, revealing an unexpectedly high degree of correlation. Thus, information derived from the molecular analysis (DNA or protein) of a particular patient provides a "molecular diagnosis," which is highly predictive of the clinical course that patient can be expected to follow. Because molecular diagnoses are independent of the patient's age, they provide a prognosis for the large majority of muscular dystrophy patients even before clinical symptoms of their disease become apparent. Such prognostic molecular diagnoses have proven particularly valuable when the patient is an isolated case, with no family history for the disorder. Prenatal genetic diagnosis of DMD or BMD may involve use of Southern blot or PCR techniques to search for a deletion in the DNA of at-risk fetuses or more complicated family linkage studies using intragenic and flanking RFLPs. More recently, assay of dystrophin content in fetal skeletal or cardiac muscle from at-risk abortuses has been accomplished, allowing definitive discrimination of affected and normal fetuses in cases in which deletion analyses and family DNA studies were equivocal. In utero fetal skeletal muscle biopsy for dystrophin protein assay has actually been accomplished in at least one at-risk pregnancy in which family DNA studies were uninformative. Dystrophin was present in skeletal muscle from this 20-week-old male fetus, and the pregnancy continued, resulting in the term birth of a healthy male infant. The future holds exciting opportunities for neonatal screening and treatment of these devastating neuromuscular diseases.
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PMID:Duchenne and Becker muscular dystrophies: genetics, prenatal diagnosis, and future prospects. 228 31

The similarity in clinical features of X-linked Becker muscular dystrophy (BMD) and the autosomal recessive limb-girdle (LGD) type of adult muscular dystrophy makes differential diagnosis of the isolated male case difficult. DNA probes complementary (cDNA) to the Duchenne/Becker muscular dystrophy gene product, dystrophin, can detect molecular deletions in 60-70% of affected subjects. Thirty-three patients with BMD or LGD (thirty isolated and three with an affected brother) were screened with a panel of cDNA probes for the whole dystrophin gene. Deletions were found in thirteen of eighteen (72%) patients with a diagnosis of BMD. Deletions were also found in four of the fifteen (27%) patients previously thought to have LGD, who were therefore reclassified as having BMD. All male patients with progressive muscular dystrophy of limb-girdle pattern should be routinely screened with these cDNA probes as a useful adjunct to their clinical diagnosis since the results have important implications for genetic counselling of affected families.
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PMID:Distinction of Becker from limb-girdle muscular dystrophy by means of dystrophin cDNA probes. 256 42

We report the ophthalmological findings of a 6-year-old boy who has features of both Aland Island eye disease (also called Forsius-Eriksson ocular albinism) and incomplete congenital stationary night blindness, as defined by Miyake, leading us to suspect that they are the same entity. This child has a deletion of part of band 21 of the short arm of the X chromosome (Xp21) and three other X-linked disorders: congenital adrenal hypoplasia, glycerol kinase deficiency, and Duchenne type muscular dystrophy. The electroretinogram showed negative scotopic and abnormal photopic waveforms that were similar, if not identical, to the electroretinographic findings in both Aland Island eye disease and X-linked incomplete congenital stationary night blindness. Because of this similarity and the defective dark adaptometry that has been reported in patients with this disorder, we believe that Aland Island eye disease is more appropriately classified as a form of congenital night blindness than as a form of ocular albinism. From our case and review of the literature, Aland Island eye disease and incomplete congenital stationary night blindness appear indistinguishable. If further studies confirm that the disorders are the same, we recommend use of the term Aland Island eye disease or Forsius-Eriksson-Miyake syndrome. We also recommend that the gene symbols CSNB1 and CSNB2 be used for complete congenital stationary night blindness and Aland disease, respectively.
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PMID:Aland Island eye disease (Forsius-Eriksson syndrome) associated with contiguous deletion syndrome at Xp21. Similarity to incomplete congenital stationary night blindness. 266 10

This is the first description of a dystrophin-deficient muscular dystrophy in domestic cats. The disorder appears to be of X-linked inheritance because it affected both males of a litter of four kittens. Immunoblotting and immunofluorescent detection of dystrophin showed dystrophin present in control cat muscle but no detectable dystrophin in either affected cat. The feline muscular dystrophy was progressive and histopathologically resembled human Duchenne/Becker muscular dystrophy except for the lack of fat infiltration and the presence of prominent hypertrophy of both muscle fibers and muscles groups in the feline disorder.
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PMID:Feline muscular dystrophy with dystrophin deficiency. 268 99

Infantile glycerol kinase deficiency (GKD) is an X-linked genetic disease characterized clinically by adrenal insufficiency and muscular dystrophy. The enzyme defect leads to increased levels of glycerol in blood and urine, which can be used for diagnosis. Without recognition of this condition, the chances for life-saving steroid treatment and for genetic counselling are missed. We report clinical, endocrinological, biochemical, and morphological findings in two non-related boys. One of them died in early infancy. The other is thriving at the age of 2 years although he is suffering from a myopathy not distinguishable from Duchenne muscular dystrophy. We discuss when to suspect and how to confirm the diagnosis of infantile GKD, and under what precautions the condition is detectable by commonly used screening procedures for inborn errors of metabolism.
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PMID:Infantile glycerol kinase deficiency--a condition requiring prompt identification. Clinical, biochemical, and morphological findings in two cases. 282 63

The distribution of HLA ABC class I antigens in human skeletal muscle obtained by needle biopsy was investigated by means of a monoclonal antibody (W6/32) and an immunoperoxidase technique. Five samples from normal individuals and twenty-nine from patients with various neuromuscular disorders were examined. Normal muscle fibres and those from patients with congenital muscular dystrophy expressed little or no class I antigens, whereas muscle fibres of patients with myositis and various X-linked muscular dystrophies showed consistently strong expression. In other neuromuscular diseases expression was more variable. The presence of class I antigens on diseased muscle fibres may render them susceptible to cytotoxic T cells; these antigens may thus have an important role in the destruction of muscle fibres.
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PMID:Increased expression of HLA ABC class I antigens by muscle fibres in Duchenne muscular dystrophy, inflammatory myopathy, and other neuromuscular disorders. 285 18

Duchenne muscular dystrophy (DMD) is an X-linked disorder affecting about 1 in 3,500 males. It is allelic with the milder Becker muscular dystrophy. The biochemical basis for both diseases is unknown and no effective treatment is available. Long-range physical mapping has shown that the DMD gene, localized in Xp21, is extremely large, exceeding 2 million base pairs. Until now, carrier detection and prenatal diagnosis has involved the use of linked restriction fragment length polymorphism markers which detect muscular dystrophy-associated deletions in about 10% of the cases. Field inversion gel electrophoresis (FIGE) allows the detection of structural rearrangements in 21 out of 39 of the DMD patients studied (54%), of which 14 (65%) were not detected by conventional methods. Large deletions seem to make up a much higher fraction of the DMD mutations than so far indicated by other methods. A region prone to deletion was located in the distal half of the gene. FIGE analysis could provide a valuable extension of information for carrier detection and prenatal diagnosis. The technique should be generally applicable to the study of diseases involving structural chromosomal rearrangements.
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PMID:Direct detection of more than 50% of the Duchenne muscular dystrophy mutations by field inversion gels. 288 48

The distribution of HLA class I and class II antigens has been investigated in cryostat sections of a series of 200 skeletal muscle biopsy specimens from patients with various neuromuscular disorders. Normal muscle fibres expressed no detectable class I antigens, whereas muscle fibres of patients with inflammatory myopathies and Duchenne (DMD) and Becker (BMD) muscular dystrophy showed consistently strong expression. In other neuromuscular diseases expression of class I antigens was more variable. No expression of class I antigens was observed on muscle fibres in samples from fetuses "at risk" for DMD and BMD or from female carriers of these disorders. The immunocytochemical assessment of HLA class I antigen expression was confirmed by a quantitative radioimmunoassay which demonstrated a 3-fold increase in the level of expression in muscle samples from patients with DMD and juvenile dermatomyositis. Class II antigen expression was never observed on muscle fibres in biopsies from normal individuals or any of the neuromuscular disorders. However, these antigens were expressed by endothelial cells present in these samples. Muscle specimens from fetuses and early in postnatal life showed very limited expression of class II antigens. They were expressed at a reduced level by about 3 months of age, but strong expression of class II antigens was not observed until about 1 year of age. The mechanism of induction of class I antigen expression in diseased muscle is not known. The appearance of class I antigens on diseased muscle may make the affected tissue a target for cytotoxic T cells and may thus have a role in muscle fibre damage in inflammatory myopathies and the X-linked muscular dystrophies.
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PMID:Expression of class I and class II MHC antigens in neuromuscular diseases. 292 49

A 23-year-old man with X-linked Becker type muscular dystrophy underwent cardiac transplantation because of dilated cardiomyopathy which was complicated by terminal heart failure. Impairment of muscle function was mild and slowly progressive, whereas the cardiac disease was severe and rapidly progressive. All four chambers of the removed heart were grossly dilated; microscopically, the myocardial fibres were hypertrophic and pale; the nuclei exhibited pleomorphism with variability in nuclear size, shape, and depth of staining.
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PMID:Cardiac transplantation in Becker muscular dystrophy. 306 35

The DNA from 68 patients with X-linked (Duchenne and Becker) muscular dystrophy belonging to 49 unrelated families was analyzed for microdeletions using 13 closely linked or gene-specific DNA-markers. Fourteen patients from eight families showed a deletion involving a least one of the markers used, giving a deletion frequency of 16%. The proportion of families with deletions was 36% in the Becker and 8% in the Duchenne form of the disease. With one exception, the extent of the deletion was different in different families. All living, affected males from the same family carried the same deletion. The extent or the localization of the deletion did not correlate with clinical features such as severity of disease or mental retardation.
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PMID:Microdeletions in patients with X-linked muscular dystrophy: molecular-clinical correlations. 316 51


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