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)

Caveolae are invaginations of the plasma membrane involved in many cellular processes, including clathrin-independent endocytosis, cholesterol transport, and signal transduction. They are characterized by the presence of caveolin proteins. Mutations that cause deficiency in caveolin-3, which is expressed exclusively in skeletal and cardiac muscle, have been linked to muscular dystrophy. Polymerase I and transcript release factor (PTRF; also known as cavin) is a caveolar-associated protein suggested to play an essential role in the formation of caveolae and the stabilization of caveolins. Here, we identified PTRF mutations in 5 nonconsanguineous patients who presented with both generalized lipodystrophy and muscular dystrophy. Muscle hypertrophy, muscle mounding, mild metabolic complications, and elevated serum creatine kinase levels were observed in these patients. Skeletal muscle biopsies revealed chronic dystrophic changes, deficiency and mislocalization of all 3 caveolin family members, and reduction of caveolae structure. We generated expression constructs recapitulating the human mutations; upon overexpression in myoblasts, these mutations resulted in PTRF mislocalization and disrupted physical interaction with caveolins. Our data confirm that PTRF is essential for formation of caveolae and proper localization of caveolins in human cells and suggest that clinical features observed in the patients with PTRF mutations are associated with a secondary deficiency of caveolins.
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PMID:Human PTRF mutations cause secondary deficiency of caveolins resulting in muscular dystrophy with generalized lipodystrophy. 2044 52

Human PTRF mutations cause secondary deficiency of caveolins resulting in muscular dystrophy with generalized lipodystrophy Hayashi et al. (2009) The Journal of Clinical Investigation 119: 2623-2633.
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PMID:Lipodystrophy and muscular dystrophy caused by PTRF mutations. 1972 76

Congenital generalized lipodystrophy (CGL), characterized by generalized absence of adipose tissue, has heterogeneous causes. Recently, a novel type of CGL complicated by muscular dystrophy was categorized as CGL4 caused by PTRF-CAVIN deficiency. However, it is unknown whether CGL4 exhibits clinical abnormalities during the infantile period. Here, we describe the youngest Japanese case of CGL4-a Japanese girl with asymptomatic high serum creatine kinase (CK) levels at 3months old. She was referred to our hospital at 5months of age because of her elevated serum CK (2528IU/L). Generalized absence of adipose tissue was first recognized at 2years of age. Mutation analysis of genes known to be responsible for CGL1-3 failed to disclose any abnormalities. Instead, analysis of the PTRF-CAVIN gene encoding PTRF-CAVIN revealed compound heterozygous mutations, one allele contained an insertion (c.696_697insC) and the other allele harbored a novel nonsense mutation (c.512C>A). Our patient had low serum leptin and adiponectin levels and insulin resistance. Pathological studies on biopsied muscle disclosed mild dystrophic change and highly reduced expression of PTRF-CAVIN. It was concluded that our PTRF-CAVIN deficient patient showed not only CGL but also asymptomatic elevation of serum CK because of her mild muscle dystrophic change.
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PMID:A Japanese child with asymptomatic elevation of serum creatine kinase shows PTRF-CAVIN mutation matching with congenital generalized lipodystrophy type 4. 2063 80

Autosomal recessive Emery Dreifuss muscular dystrophy (AR-EDMD) is rare, with few reports in the medical literature. We describe the first cases of AR-EDMD and autosomal dominant familial partial lipodystrophy (FPLD) in the Hutterite population resulting from homozygous or heterozygous R482Q mutations in the lamin A/C gene (LMNA). Heterozygosity for LMNA R482Q mutation causes FPLD, which is associated with increased risk of hyperlipidemia and hypertension. The overall carrier frequency of the R482Q mutation in Dariusleut and Leherleut Hutterites in Alberta was found to be 1.45%. Homozygosity for this mutation has not been previously reported and here resulted in a combination of generalized lipodystrophy and EDMD. Knowledge that the LMNA R482Q mutation is present in this population is important for genetic counseling, surveillance, and management of the associated disorders.
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PMID:Homozygous lamin A/C familial lipodystrophy R482Q mutation in autosomal recessive Emery Dreifuss muscular dystrophy. 2331 86

A boy with congenital generalized lipodystrophy type 4 with muscular dystrophy presented in infancy with delay in motor milestones and a persistent elevation of CK. There was no associated mental retardation. He was followed up to 3 years and 11 months; he had a homozygous c.696_697insC mutation in polymerase I and transcript release factor (PTRF). He started to walk at 2 years and 6 months although he did not have mental retardation. Insulin resistance appeared at 3 years and 11 months of age. PTRF immunostaining positivity was absent in the muscle but caveolin-3 was preserved in the sarcolemma at 16 months of age. Secondary deficiency of caveolins may be closely associated with disease progression.
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PMID:Congenital generalized lipodystrophy type 4 with muscular dystrophy: clinical and pathological manifestations in early childhood. 2348 63

The LMNA gene contains 12 exons and encodes lamins A and C by alternative splicing within exon 10. While mutations in lamin A specific residues cause several diseases including lipodystrophy, progeria, muscular dystrophy, neuropathy, and cardiomyopathy, only three families with mutations in lamin C-specific residues are reported with cardiomyopathy, neuropathy, and muscular dystrophy so far. We now report two brothers with juvenile-onset generalized lipodystrophy due to a lamin C-specific mutation. The proband, a 23-year-old Caucasian male was reported to have generalized lipodystrophy at 3 weeks of age, developed diabetes, hypertriglyceridemia, hypertension and liver problems and died with complications of cirrhosis, and kidney failure. His younger brother, a 37-year-old Caucasian male developed generalized lipodystrophy around 2 years of age and was diagnosed with diabetes, hypertriglyceridemia, fatty liver, and hypertension at 36 years of age. Their father also died of end stage renal disease at age 52 years. Exome sequencing of the proband revealed an extremely rare missense heterozygous variant c.1711_1712CG>TC; p.(Arg571Ser) in LMNA which was confirmed by Sanger sequencing in both the patients. Interestingly, the mutation had no effect on mRNA splicing or relative expression of lamin A or C mRNA and protein in the lymphoblasts. Our observations suggest that mutant lamin C disrupts its interaction with other cellular proteins resulting in generalized lipodystrophy due to defective development and maintenance of adipose tissue.
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PMID:Juvenile-onset generalized lipodystrophy due to a novel heterozygous missense LMNA mutation affecting lamin C. 2868 29

Caveolinopathies, caused by CAV3 mutations, can include several phenotypes such as rippling muscle disease, limb-girdle muscular dystrophy type 1C, distal myopathy, familial hypertrophic cardiomyopathy, and idiopathic hyperCKemia. Here we present characteristic skeletal muscle imaging findings in four patients with genetically defined childhood-onset RMD caused by CAV3 mutations and in one patient with congenital generalized lipodystrophy type 4 with muscular dystrophy due to polymerase I and transcript release factor (PTRF) mutations, which may have caused secondary deficiency of caveolin-3. Muscle MRI revealed that the rectus femoris and semitendinosus muscles were most commonly affected in the rippling muscle disease patients. Peripheral changes in the rectus femoris were specific and observed even in one of the younger patients in this study. Furthermore, muscle involvement extended to the semitendinosus muscles, biceps femoris, and gracilis with disease progression or increase in its severity. Similar patterns of involvement were observed on reviewing skeletal muscle images of various previously reported phenotypes of caveolinopathy; interestingly, patients with secondary deficiency of caveolin due to PTRF mutations revealed the same pattern. Thus, primary caveolinopathies and secondary deficiency of caveolin demonstrated specific findings on skeletal muscle imaging, regardless of the broad phenotypic spectrum of these two conditions.
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PMID:Characteristic findings of skeletal muscle MRI in caveolinopathies. 3017 72

Congenital generalized lipodystrophy type 4 (CGL4) is a rare disease caused by mutations in the gene polymerase I and transcript release factor (PTRF), the main symptoms of which are systemic reductions in adipose tissue and muscular dystrophy. The strategy of treating CGL4 is to improve the insulin resistance and hypertriglyceridemia that result from systemic reductions in adipose tissue. Metreleptin, a synthetic analog of human leptin, is effective against generalized lipodystrophies; however, there are no reports of the use of metreleptin in the treatment of CGL4. Herein, we discuss the treatment of a six-year-old boy diagnosed with CGL4 due to a homozygous mutation in PTRF with metreleptin. His serum triglyceride level and homeostasis model assessment of insulin resistance (HOMA-IR) value decreased after two months of metreleptin treatment. However, the efficacy of metreleptin gradually decreased, and the treatment was suspended because anaphylaxis occurred after the dosage administered was increased. Subsequently, his serum triglyceride level and HOMA-IR value significantly increased. Anti-metreleptin-neutralizing antibodies were detected in his serum, which suggested that these antibodies reduced the efficacy of metreleptin and caused increased hypersensitivity. Thus, metreleptin appeared to be efficacious in the treatment of CGL4 in the short term, although an adverse immune response resulted in treatment suspension. Further studies are needed to evaluate metreleptin treatments for CGL4.
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PMID:Metreleptin treatment for congenital generalized lipodystrophy type 4 (CGL4): a case report. 3074 27