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

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

Adult male patients affected with Becker (BMD, N = 22), limb girdle (LGMD, N = 22) and facioscapulohumeral (FSHMD, N = 18) muscular dystrophy were interviewed to assess for the first time how the disease's severity and recurrence risk (RR) magnitude alter their social adjustment. BMD (X-linked recessive) is the severest form and confers an intermediate RR because all daughters will be carriers, LGMD (autosomal-recessive) is moderately severe with a low RR in the absence of consanguineous marriage, and FSHMD (autosomal-dominant) is clinically the mildest of these three forms of MD but with the highest RR, of 50%. Results of the semistructured questionnaire [WHO (1988): Psychiatric Disability Assessment Schedule] showed no significant difference between the three clinical groups, but more severely handicapped patients as well as patients belonging to lower socioeconomic levels from all clinical groups showed poorer social adjustment. Taken together, myopathic patients displayed intermediate social dysfunction compared to controls and schizophrenics studied by Jablensky [1988: WHO Psychiatric Disability Assessment Schedule]. Since the items of major dysfunction proportion among myopathic patients concern intimate relationships (70%), interest in working among those unemployed (67%), and social isolation (53%), emotional support and social and legal assistance should concentrate on these aspects. Interestingly, the results of this study also suggest that high RRs do not affect relationships to the opposite sex.
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PMID:Social adjustment in adult males affected with progressive muscular dystrophy. 951 80

The reproductive history of 177 male patients affected with Becker (BMD) (n=69), limb-girdle (LGMD) (n=54), and facioscapulohumeral (FSHMD) (n=54) muscular dystrophy (MD) was analysed according to severity of the disease (BMD>LGMD>FSHMD) and magnitude of recurrence risk (RR) (high for FSHMD, intermediate for BMD, and low for LGMD). Additionally, 62 male patients were interviewed on psychosocial issues, in order to disentangle the factors influencing reproductive decisions among patients affected with MD. Among male adults, significantly more FSHMD than LGMD or BMD patients were married and had children. Age specific reproductive outcome was 0.31-0.32 for BMD, 0.51-0.62 for LGMD, and 0.58-1.02 for FSHMD, reflecting the influence of the disease's severity. High RRs did not significantly diminish reproduction after genetic counselling or correlate with less prospective desire for children. Instead, early onset, severity of the disease, and past reproductive history were found to diminish reproductive outcome after genetic counselling, and prospective family planning was also found to be influenced by past reproductive history as well as by emotional/sexual dysfunction with the opposite sex.
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PMID:How the magnitude of clinical severity and recurrence risk affects reproductive decisions in adult males with different forms of progressive muscular dystrophy. 954 Nov 1

Data from 6 years of experience in molecular diagnosis of Duchenne (DMD) and Becker (BMD) muscular dystrophy in Southern France are reported. DMD and BMD patients have been extensively analyzed for deletions and for point mutations in the dystrophin gene. By scanning the whole coding sequence as reverse-transcribed from lymphocytes or muscular RNA by the protein truncation test, we have reached a minimum of an 86% detection rate for point mutations responsible for DMD; these mutations consist of nonsense, frameshifting, and splicing mutations. Four of 12 small alterations identified in our sample are novel and described in this study. We also present an improved protocol for the automated detection of fluorescently labeled duplex polymerase chain reactions of six known intragenic microsatellites (Dys II, TG 15, STRs 44, 45, 49, and 50). Accurate sizing of the alleles at each locus was performed, and we elucidated the sequence of several repeat units. Allele frequencies at each of the six microsatellite loci and at one restriction fragment length polymorphism site (intron 16/TaqI) were defined in a sample of normal, DMD, and BMD X chromosomes from Southern France. The determination of the grandparental origin of either deletions or point mutations revealed differences depending on the type of the mutation, with most of the deletions occurring in oogenesis and most of the point mutations occurring in spermatogenesis.
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PMID:Mutation analysis of the dystrophin gene in Southern French DMD or BMD families: from Southern blot to protein truncation test. 954 49

In order to screen for cardiac abnormalities, we prospectively studied 15 patients (age 8-25 years, mean 15.5 years) with Duchenne's (DMD) (n = 9) and Becker's (BMD) (n = 6) muscular dystrophy using the echocardiogram. Data were compared to a control group of 92 healthy individuals (age 7.9-25 years, mean 14.3 years). Left ventricular filling in diastole showed a different pattern when comparing echocardiographic Doppler results in patients and controls: Patients had lower peak velocity of early left ventricular diastolic filling (E-vmax)(P < 0.0001) and smaller time velocity integral of the E-wave (E-tvi)(P < 0.0001). In contrast, the atrial component (A-vmax, A-tvi) of diastolic filling in DMD/ BMD showed no significant difference to controls. The mean area of the mitral valve orifice was significantly larger in patients (P < 0.0001) without presence of mitral regurgitation. Systolic left ventricular function was significantly impaired in the DMD/BMD group; we found lower heart rate corrected fiber shortening velocity VCFc (P < 0.001) and higher peak systolic wall stress (P < 0.001) in DMD/BMD. In 8 of 15 patients, peak systolic wall stress was above 95th percentile of controls. In 6 of 15 patients, VCFc was lower than the 5th percentile of controls. Systolic and diastolic myocardial impairment was found even in young patients and at low stages of disability--equally among patients with DMD or BMD. Diastolic left ventricular impairment predominantly affected the early diastolic filling, but atrial compensation was poor. Peak systolic wall stress measurements were particularly useful in patients with CMP, reflecting the left ventricular afterload.
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PMID:X-chromosomal (p21) muscular dystrophy and left ventricular diastolic and systolic function. 956 5

The integrins are a large family of heterodimeric transmembrane cellular receptors which mediate the association between the extracellular matrix (ECM) and cytoskeletal proteins. The alpha7beta1 integrin is a major laminin binding integrin in skeletal and cardiac muscle and is thought to be involved in myogenic differentiation and migration processes. The main binding partners of the alpha7 integrin are laminin-1 (alpha1-beta1-gamma1), laminin-2 (alpha2-beta1-gamma1) and laminin-4 (alpha2-beta2-gamma1). Targeted deletion of the gene for the alpha7 integrin subunit (ITGA7) in mice leads to a novel form of muscular dystrophy. In the present study we have investigated the expression of two alternative splice variants, the alpha7B and beta1D integrin subunits, in normal human skeletal muscle, as well as in various forms of muscular dystrophy. In normal human skeletal muscle the expression of the alpha7 integrin subunit appeared to be developmentally regulated: it was first detected at 2 years of age. In contrast, the beta1D integrin could be detected in immature and mature muscle in the sarcolemma of normal fetal skeletal muscle at 18 weeks gestation. The expression of alpha7B integrin was significantly reduced at the sarcolemma in six patients with laminin alpha2 chain deficient congenital muscular dystrophy (CMD) (age >2 years). However, this reduction was not correlated with the amount of laminin alpha2 chain expressed. In contrast, the expression of the laminin alpha2 chain was not altered in the skeletal muscle of the alpha7 knock-out mice. These data argue in favor that there is not a tight correlation between the expression of the alpha7 integrin subunit and that of the laminin alpha2 chain in either human or murine dystrophic muscle. Interestingly, in dystrophinopathies (Duchenne and Becker muscular dystrophy; DMD/BMD) expression of alpha7B was upregulated irrespective of the level of dystrophin expression as shown by a strong sarcolemmal staining pattern even in young boys (age <2 years). The expression of the beta1D integrin subunit was not altered in any of our patients with different types of muscular dystrophy. In contrast, sarcolemmal expression of beta1D integrin was significantly reduced in the alpha7 integrin knock-out mice, whereas the expression of the components of the DGC was not altered. The secondary loss of alpha7B in laminin alpha2 chain deficiency defines a biochemical change in the composition of the plasma membrane resulting from a primary protein deficiency in the basal lamina. These findings, in addition to the occurrence of a muscular dystrophy in alpha7 deficient mice, implies that the alpha7B integrin is an important laminin receptor within the plasma membrane which plays a significant role in skeletal muscle function and stability.
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PMID:Secondary reduction of alpha7B integrin in laminin alpha2 deficient congenital muscular dystrophy supports an additional transmembrane link in skeletal muscle. 1037 Oct 75

The clinical and molecular features of 25 Duchenne (DMD), two intermediate (D/BMD) and three Becker (BMD) muscular dystrophy patients from 26 unrelated families were evaluated. Early psychomotor development was normal in patients with D/BMD and BMD. Learning to walk independently after 15 months of age was a risk sign of DMD in nine (36%) patients. Abnormality in crawling was seen in 13 (54%) patients with DMD. These boys demonstrated initial symptoms earlier than those who learned to crawl normally. Mental retardation was established in five (20%) patients with DMD. Deletions in the dystrophin gene were found in 11 families (48%). They were accumulated (9/11, 82%) in the distal region of the gene.
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PMID:Duchenne and Becker muscular dystrophies: an Estonian experience. 1039 46

A cross-sectional study in a cohort of DNA proven carriers of Duchenne (DMD) and Becker (BMD) muscular dystrophy was undertaken with the following objectives: (1) to estimate the frequency of electrocardiographic (ECG) and echocardiographic abnormalities; (2) to establish the proportion of carriers with dilated cardiomyopathy and (3) to assess possible associations between dilated cardiomyopathy and genotype. One hundred and twenty nine DMD and BMD carriers, aged 18-60 years, were traced through the files of the central register kept at the department of Human Genetics in Leiden. Investigations included full medical history, physical examination, ECG and two-dimensional and M-mode echocardiographic examination. Forty-seven percent had ECG changes. Thirty-six percent (DMD 41%, BMD 27%) had at least one abnormality as is usually found in the male patients. Echocardiographic examination was abnormal in 36% (DMD 38%, BMD 34%). Dilated cardiomyopathy was found in seven DMD carriers (8%), and in none of BMD carriers. In addition, 18% had left ventricle dilatation (DMD 19%, BMD 16%). Only 38% had a completely normal investigation of the heart. We found no association between genotype and cardiac manifestations. Our study underlines that cardiac involvement is part of the dystrophinopathies. Carriers should be told about the increased risk of this complication when asking genetic advice. It also implicates that a complete cardiological evaluation should be performed at least once in all carriers. If left ventricle dilatation or dilated cardiomyopathy is present a yearly follow up is needed, in order to start timely therapy.
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PMID:Cardiac involvement in carriers of Duchenne and Becker muscular dystrophy. 1040 58

Episodes of acute myoglobinuria or cardiac arrest were occasionally complicated in general anesthesia of patients with Duchenne or Becker muscular dystrophy (DMD/BMD). Whether these complications are malignant hyperthermia (MH) or not has several times been discussed. In the present study, we applied the clinical grading scale (CGS) of Larach and modified criteria of caffeine contracture test of the skinned fiber (sIVCT) to solve this problem. When the CGS was applied to reported MH-like episodes of DMD/BMD cases, 9 out of 20 cases were classed as almost certain or very likely MH. According to results of sIVCT in 11 patients with DMD/BMD, 5 patients were judged as MHS (MH-susceptible) and 3 as MHE (MH-equivocal). The diagnostic specificity of present MHS criteria was 100% for the fulminant MH. A possible "false positive" result in European IVCT has been discussed in relation to myopathy such as muscular dystrophy. When we applied our sIVCT to the muscle of mdx mouse, caffeine contracture was rather reduced compared to controls. Present study suggested that a true MH was complicated in some cases of DMD/BMD. In certain stage of muscular degeneration, patients with DMD/BMD become susceptible to MH, probably temporarily, but exact mechanism still awaits clarification.
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PMID:[Malignant hyperthermia of Duchenne muscular dystrophy: application of clinical grading scale and caffeine contracture of skinned muscle fibers]. 1100 22


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