Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.54 (calpain 3)
 430 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dysferlin is the protein product of the DYSF gene mapped at 2p31, which mutations cause limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy. To date, nine autosomal recessive forms (AR-LGMD) have been identified: four genes, which code for the sarcoglycan glycoproteins, are associated with both mild and severe forms, the sarcoglycanopathies (LGMD2C, 2D, 2E and 2F). The other five forms, usually causing a milder phenotype are LGMD2A (calpain 3), LGMD2B (dysferlin), LGMD2G (telethonin), LGMD2H (9q31-11), and LGMD21 (19q13.3). We studied dysferlin expression in a total of 176 patients, from 166 LGMD families: 12 LGMD2B patients, 70 with other known forms of muscular dystrophies (LGMD2A, sarcoglycanopathies, LGMD2G), in an attempt to assess the effect of the primary gene-product deficiency on dysferlin. In addition, 94 still unclassified LGMD families were screened for dysferlin deficiency. In eight LGMD2B patients from five families, no dysferlin was observed in muscle biopsies, both through immunofluorescence (IF) and Western blot methodologies, while in two families, a very faint band was detected. Both patterns, negative or very faint bands, were concordant in patients belonging to the same families, suggesting that dysferlin deficiency is specific to LGMD2B. Myoferlin, the newly identified homologue of dysferlin was studied for the first time in LGMD2B patients. Since no difference was observed between patients mildly and severely affected, this protein do not seem to modify the phenotype in the present dysferlin-deficient patients. Dystrophin, sarcoglycans, and telethonin were normal in all LGMD2B patients, while patients with sarcoglycanopathies (2C, 2D, and 2E), LGMD2A, LGMD2G, and DMD showed the presence of a normal dysferlin band by Western blot and a positive pattern on IF. These data suggest that there is no interaction between dysferlin and these proteins. However, calpain analysis showed a weaker band in four patients from two families with intra-familial concordance. Therefore, this secondary deficiency of calpain in LGMD2B families, may indicate an interaction between dysferlin and calpain in muscle. Dysferlin was also present in cultured myotubes, in chorionic villus, and in the skin. Dysferlin deficiency was found in 24 out of a total of 166 Brazilian AR-LGMD families screened for muscle proteins (approximately 14%), thus representing the second most frequent known LGMD form, after calpainopathy, in our population.
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PMID:Dysferlin protein analysis in limb-girdle muscular dystrophies. 1166 64

Neuromuscular diseases (NMDs) include a broad range of disorders affecting muscles, nerves and neuromuscular junctions. Their overlapping phenotypes and heterogeneous genetic nature have created challenges in diagnosis which calls for the implementation of massive parallel sequencing as a candidate strategy to increase the diagnostic yield. In this study, total of 45 patients, mostly offspring of consanguineous marriages were examined using whole exome sequencing. Data analysis was performed to identify the most probable pathogenic rare variants in known NMD genes which led to identification of causal variants for 33 out of 45 patients (73.3%) in the following known genes: CAPN3, Col6A1, Col6A3, DMD, DYSF, FHL1, GJB1, ISPD, LAMA2, LMNA, PLEC1, RYR1, SGCA, SGCB, SYNE1, TNNT1 and 22 novel pathogenic variants were detected. Today, the advantage of whole exome sequencing in clinical diagnostic strategies of heterogeneous disorders is clear. In this cohort, a diagnostic yield of 73.3% was achieved which is quite high compared to the overall reported diagnostic yield of 25% to 50%. This could be explained by the consanguineous background of these patients and is another strong advantage of offering clinical exome sequencing in diagnostic laboratories, especially in populations with high rate of consanguinity.
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PMID:Improved diagnostic yield of neuromuscular disorders applying clinical exome sequencing in patients arising from a consanguineous population. 2723 31

Inherited muscular disorders (IMDs) are clinically and genetically heterogeneous genetic disorders. We investigated the mutational spectrum and genotype-phenotype correlations in Korean patients with IMD. We developed a targeted panel of 69 known IMD genes and recruited a total of 209 Korean patients with IMD. Targeted capture sequencing identified 994 different variants. Among them, 98 variants were classified as pathogenic/likely pathogenic variants; 38 were novel variations. A total of 39 patients had the pathogenic/likely pathogenic variants. Among them, 75 (36%) patients were genetically confirmed, and 18 (9%) patients had one heterozygous variant of recessive myopathy. However, two genetically confirmed patients had an additional heterozygous variant of another recessive myopathy. Four patients with one heterozygous variant of a recessive myopathy showed different phenotypes, compared with the known phenotype of the identified gene. The major causative genes of Korean patients with IMDs were DMD (19 patients), COL6A1 (9), DYSF (9), GNE (7), LMNA (7), CAPN3 (6), and RYR1 (5). This study showed the mutational and clinical spectra in Korean patients with IMD and confirmed the usefulness of strategies utilizing targeted sequencing.
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PMID:Discovery of pathogenic variants in a large Korean cohort of inherited muscular disorders. 2736 42

The current study characterizes a cohort of limb-girdle muscular dystrophy (LGMD) in the United States using whole-exome sequencing. Fifty-five families affected by LGMD were recruited using an institutionally approved protocol. Exome sequencing was performed on probands and selected parental samples. Pathogenic mutations and cosegregation patterns were confirmed by Sanger sequencing. Twenty-two families (40%) had novel and previously reported pathogenic mutations, primarily in LGMD genes, and also in genes for Duchenne muscular dystrophy, facioscapulohumeral muscular dystrophy, congenital myopathy, myofibrillar myopathy, inclusion body myopathy and Pompe disease. One family was diagnosed via clinical testing. Dominant mutations were identified in COL6A1, COL6A3, FLNC, LMNA, RYR1, SMCHD1 and VCP, recessive mutations in ANO5, CAPN3, GAA, LAMA2, SGCA and SGCG, and X-linked mutations in DMD. A previously reported variant in DMD was confirmed to be benign. Exome sequencing is a powerful diagnostic tool for LGMD. Despite careful phenotypic screening, pathogenic mutations were found in other muscle disease genes, largely accounting for the increased sensitivity of exome sequencing. Our experience suggests that broad sequencing panels are useful for these analyses because of the phenotypic overlap of many neuromuscular conditions. The confirmation of a benign DMD variant illustrates the potential of exome sequencing to help determine pathogenicity.
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PMID:The sensitivity of exome sequencing in identifying pathogenic mutations for LGMD in the United States. 2770 73