Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1762617 (weakness)
 37,932 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

No specific diagnostic test is available to identify patients with proximal myotonic myopathy and to distinguish them from common disorders causing similar complaints. We describe three patients from three separate families who were initially diagnosed as having hypothyroid myopathy. Proximal weakness, stiffness and myotonia have persisted in each patient (2-10 years) despite the restoration of the euthyroid state. A familial pattern of autosomal dominant inheritance for proximal weakness, myotonia, and cataracts was clearly identified in one family and was likely in the other two families. DNA testing showed normal size of CTG repeat in the gene for myotonic dystrophy. The clinical presentation of these three patients strongly suggests that hypothyroidism can unmask PROMM in asymptomatic individuals who carry the genetic abnormality. Other cases of 'hypothyroid myopathy' may represent examples of unmasked PROMM.
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PMID:Hypothyroidism unmasking proximal myotonic myopathy. 1073 62

We report 13 French patients with proximal myotonic myopathy. PROMM is a recently delineated multisystem disorder with dystrophic myopathy, myotonia and cataracts. This syndrome is genetically distinct from myotonic dystrophy (DM) by the absence of abnormal CTG repeat expansion. The geographical origin varies but 4 families originated from Poland. Of late onset, muscle weakness is diffuse and predominantly affected proximal and axial muscles. Facial involvement and myotonia were moderate or absent, but in all cases myotonic discharges were detected on EMG. 6 patients suffered from myalgia. Cataracts occurred in 11 patients, mainly indistinguishable from those in DM. Cardiac arrythmia occurred in 7 patients. Muscle biopsy revealed rare structural changes of the muscle fibers and selective type I atrophy, common in DM, could not be found on morphometric analysis. PROMM has a distinct clinical spectrum from DM which includes a predominantly proximal muscle weakness, with troubling pain, a more favourable prognosis and a different histopathological pattern.
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PMID:[Proximal myotonial myopathy (PROMM): clinical and histology study]. 1128 67

Myotonic disorders are characterised by slowed muscle relaxation and myotonic discharges in the electromyogram. "Pure" myotonic disorders affect only muscle and can be separated into ion channel disorders affecting either the chloride channel (myotonia congenita Thomsen or myotonia congenita Becker) or those affecting the sodium channel (paramyotonia, hyperkalemic periodic paralysis, and myotonia fluctuans). The genetic defects in these disorders are point mutations or deletions within the respective channel genes. A second group of myotonias consists of multisystem disorders with muscle weakness and atrophy plus extramuscular symptoms and signs including cardiac arrhythmias, cataracts, hypogonadism, and pain. Classic myotonic dystrophy (Steinert's disease or DM 1), and proximal myotonic myopathy (PROMM or Ricker's syndrome) are the major syndromes. PROMM is characterised by predominantly proximal muscle weakness and myalgias. Similarly to DM 1, anticipation also occurs in PROMM, but the disease course is usually milder. Steinert's disease belongs to the group of trinucleotide repeat-associated disorders. The DM 1 mutation is an unstable CTG trinucleotide repeat expansion on chromosome 19q13.3 which is diagnostic for the disease. A number of families with PROMM have been linked to a gene locus on chromosome 3q, but the mutation is still unknown. Therefore, direct molecular genetic testing for PROMM is not yet possible.
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PMID:[Myotonic dystrophy (DM/Curschmann-Steinert disease) and proximal myotonic myopathy (PROMM/Ricker syndrome). Myotonic muscle diseases with multisystemic manifestations]. 1151 2

Myotonic dystrophy type 2 (DM2) is a clinically but not genetically heterogeneous, multisystem disorder, that is clinically similar to, but distinct from myotonic dystrophy type 1 (DM1). Initially, different phenotypes of DM2 were described by Ricker (proximal myotonic myopathy, PROMM), Ranum (myotonic dystrophy 2, DM2) and Udd (proximal myotonic dystrophy, PDM). Clinical features these three phenotypes had in common were diffuse, proximal or distal weakness, wasting, myotonia, cataract, cerebral, endocrine and cardiac abnormalities. Initially, the clinical differences between DM1 and PROMM seemed unmistakable, but meanwhile it has become apparent that the clinical differences between these entities are blurring. In 1999, Day et al., Meola et al. and Ricker et al. mapped the mutated gene of all three phenotypes to chromosome 3q. In 2001, the three different phenotypes were found to rely on the same mutation in the ZNF9 gene on chromosome 3q21.3. Although DM2 may be clinically heterogeneous, it is by result of a mutation in a single gene. The mutation responsible for DM2 is a CCTG-repeat expansion of 75-11 000 repeats in intron 1 of the ZNF9 gene on chromosome 3q21.3. Because of the clinical heterogeneity, the diagnosis of DM2 should rely on DNA analysis alone.
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PMID:Myotonic dystrophy type 2. 1222 Mar 74

The myotonic disorders, including the myotonic dystrophies (myotonic dystrophy type 1, DM1; myotonic dystrophy type 2, DM2/PROMM/PDM), the muscle channelopathies or non-dystrophic myotonias (chloride, sodium, calcium and potassium channelopathies) are all characterized by myotonia and muscle weakness despite different pathophysiology involved in these disorders. Myotonia may affect the eye, facial and jaw muscles as well as the hands and legs. It may be painful and disabling. Muscle weakness may be episodical as in the paralytic attacks of the sodium and calcium channelopathies or culminate in permanent muscle weakness as in the calcium channelopathies and some sodium channelopathies associated to specific point mutations. The severity of myotonia may fluctuate in the myotonic dystrophies, but weakness is usually fixed, affecting neck flexors, facial and jaw muscles as well as proximal and distal muscles of the limbs. Despite the recent progress in molecular genetics the precise mechanisms responsible for myotonia and weakness are not fully understood and there is no standardized treatment strategy. We present a review of selected treatment trials in the myotonic disorders and the muscle channelopathies, and discuss our experience in the treatment of myotonia and muscle weakness, with reference to the limits and advantages of treatment trials in this field.
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PMID:Treatment in myotonia and periodic paralysis. 1526 62

In myotonic dystrophy type 2 (DM2/PROMM), cardiac muscle involvement is usually more benign than in DM1, but clinically severe cardiomyopathy has been reported in some patients. Using a novel method of magnetic resonance spectroscopy (MRS), we examined the left ventricular myocardium and the left gastrocnemius muscle in 11 unselected DM2/PROMM patients without overt cardiac disease. Data on cardiac morphology and function were obtained by gradient echo two-dimensional cine magnetic resonance imaging (MRI); no significant differences were found between DM2 patients and healthy controls, but using a median split approach older patients showed mildly increased left ventricular (LV) volumes, i.e., 59% increase of end-systolic volume index (ESVI) and 35% increase of end-diastolic volume index (EDVI), and an increase of LV mass (26%). On cardiac MRS, DM2/PROMM patients showed a reduction of phosphocreatine (PCr) and adenosine triphosphate (ATP) by 25 and 20% compared to matched healthy controls. No significant differences were found between younger and older patients. In skeletal muscle of the DM2 patients, no significant decrease of PCr and ATP concentrations was found. However, in older patients, who commonly show overt hip flexor muscle weakness, we observed reduced values for PCr and ATP. Our MRS and MRI findings reveal evidence for subclinical cardiomyopathy in DM2/PROMM patients without overt heart disease. Future prospective studies are needed to clarify the risk of developing overt cardiac disease in DM2 and to define prognostic factors.
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PMID:Cardiac and skeletal muscle involvement in myotonic dystrophy type 2 (DM2): a quantitative 31P-MRS and MRI study. 1545 41

The acyl-CoA-binding protein (ACBP)/diazepam binding inhibitor is an intracellular protein that binds C(14)-C(22) acyl-CoA esters and is thought to act as an acyl-CoA transporter. In vitro analyses have indicated that ACBP can transport acyl-CoA esters between different enzymatic systems; however, little is known about the in vivo function in mammalian cells. We have generated mice with targeted disruption of ACBP (ACBP(-/-)). These mice are viable and fertile and develop normally. However, around weaning, the ACBP(-/-) mice go through a crisis with overall weakness and a slightly decreased growth rate. Using microarray analysis, we show that the liver of ACBP(-/-) mice displays a significantly delayed adaptation to weaning with late induction of target genes of the sterol regulatory element-binding protein (SREBP) family. As a result, hepatic de novo cholesterogenesis is decreased at weaning. The delayed induction of SREBP target genes around weaning is caused by a compromised processing and decreased expression of SREBP precursors, leading to reduced binding of SREBP to target sites in chromatin. In conclusion, lack of ACBP interferes with the normal metabolic adaptation to weaning and leads to delayed induction of the lipogenic gene program in the liver.
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PMID:Disruption of the acyl-CoA-binding protein gene delays hepatic adaptation to metabolic changes at weaning. 2110 27

Myotonia is characterized by hyperexcitability of the muscle cell membrane. Myotonic disorders are divided into two main categories: non-dystrophic and dystrophic myotonias. The non-dystrophic myotonias involve solely the muscle system, whereas the dystrophic myotonias are characterized by multisystem involvement and additional muscle weakness. Each category is further subdivided into different groups according to additional clinical features or/and underlying genetic defects. However, the phenotypes and the pathological mechanisms of these myotonic disorders are still not entirely understood. Currently, four genes are identified to be involved in myotonia: the muscle voltage-gated sodium and chloride channel genes SCN4A and CLCN1, the myotonic dystrophy protein kinase (DMPK) gene, and the CCHC-type zinc finger, nucleic acid binding protein gene CNBP. Additional gene(s) and/or modifying factor(s) remain to be identified. In this study, we investigated a large Norwegian family with clinically different presentations of myotonic disorders. Molecular analysis revealed CCTG repeat expansions in the CNBP gene in all affected members, confirming that they have myotonic dystrophy type 2. However, a CLCN1 mutation c.1238C>G, causing p.Phe413Cys, was also identified in several affected family members. Heterozygosity for p.Phe413Cys seems to exaggerate the severity of myotonia and thereby, to some degree, contributing to the pronounced variability in the myotonic phenotype in this family.
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PMID:Myotonia congenita and myotonic dystrophy in the same family: coexistence of a CLCN1 mutation and expansion in the CNBP (ZNF9) gene. 2120 98