Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Muscular Atrophy”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources

[Detection of SMN gene deletions in spinal muscular atrophy].

OBJECTIVE: Survival motor neuron gene(SMN) and neuronal apoptosis inhibitory protein gene (NAIP) have been identified as the candidates of progressive spinal muscular atrophy (SMA)-determining genes. The aims of this study were to investigate the absence of SMN gene exon 7 in Chinese SMA patients, to confirm the relationship between the deletion of the SMN and SMA further, and to establish methods for gene diagnosis and prenatal diagnosis of SMA. METHODS: PCR-SSCP with silver staining method was used to detect the genomic DNA of 37 SMA patients and 30 normal individuals for deletions of SMN exon 7. RESULTS: Homozygous deletion of the SMN exon 7 was identified in 86.7%(13/15) of type I SMA patients and 86.4%(19/22) of type II patients. In the 88 controls (including parents of patients and normal individuals), homozygous absence of SMA exon 7 was only found in a mother of a patient. CONCLUSION: The data support that homozygous absence of SMN exon 7 is strongly associated with SMA. The percentage of homozygous deletions in this study is almost as high as that reported by other researchers. This method is useful, reliable and effective for gene diagnosis and prenatal diagnosis of SMA.

Cyclic AMP Response Element-Binding Protein↗

Improved single-cell protocol for preimplantation genetic diagnosis of spinal muscular atrophy.

OBJECTIVE: To develop and validate a simple and reliable single-cell analysis protocol for the preimplantation genetic diagnosis (PGD) of spinal muscular atrophy (SMA). DESIGN: Molecular tests based on specific enzymatic digestion have already been described for SMA diagnosis. We modified the amplified DNA fragments so as to introduce a novel restriction site that provides an internal control for the completeness of the digestion. SETTING: The genetics and reproduction departments of two teaching hospitals. PATIENT(S): Six informed couples at risk of transmitting SMA. INTERVENTION(S): All patients underwent standard procedures associated with intracytoplasmic sperm injection. MAIN OUTCOME MEASURE(S): Improvement of SMA diagnostic efficiency and accuracy on single cell. RESULT(S): One hundred fifty lymphocytes were analyzed with our protocol. One hundred percent diagnostic accuracy was achieved from both homozygous normal and SMN1-deleted leukocytes. Successful molecular analysis was achieved for 36 of 42 biopsied embryos (86%). Twenty-five normal embryos were transferred, but no pregnancy was achieved. CONCLUSION(S): We developed an improved protocol for PGD of SMA that is simple, robust, and accurate; unfortunately, no pregnancies were achieved for any of the six patients who have undergone PGD in the program thus far.

Base Sequence↗

Expression of the SMN gene, the spinal muscular atrophy determining gene, in the mammalian central nervous system.

The survival motor neuron (SMN) gene is the putative disease gene for human spinal muscular atrophy (SMA), an autosomal recessive disorder characterized by progressive degeneration of lower motor neurons. Two copies of the gene, centromeric and telomeric, are present in the same 5q13 chromosomal region in humans. However, only the telomeric gene is affected in SMA. The SMN gene(s) encode(s) a novel protein of unknown function. To gain insights into the role of SMN in neurons, we have identified the SMN gene ortholog in the rat, and investigated SMN expression in the CNS of rat, monkey and humans by immunocytochemistry and in situ hybridization experiments. Antibodies against the SMN amino-terminus specifically recognized a single protein identical to the in vitro translation products of human and rat SMN cDNAs. The SMN gene transcript and product were widely but unevenly expressed throughout cerebral and spinal cord areas. The SMN protein was localized mainly in the cytoplasm of specific neuronal systems, and it was particularly expressed in lower motor neurons of newborn and adult animals. Likewise, a strong hybridization signal was detected in lamina IX of the spinal ventral horn. These results support the relevance of SMN for the motor neuron function and the pathogenetic role of the SMN gene in the neuronal degeneration associated with SMA.

Amino Acid Sequence↗

[Distribution of androgen receptors in bulbo-spinal muscular atrophy].

Immunohistochemical staining with anti-androgen receptor (AR) antibody was performed in skeletal muscle specimens obtained from 3 cases with bulbo-spinal muscular atrophy (BSMA) and 12 cases with other neuromuscular disease. Anti-AR antibody staining was found exclusively in the muscle nuclei of Type 2A fibers in all of the 3 cases. But there was no positive staining in the muscle nuclei of other disease. As above mentioned, very specific immuno-staining of AR in skeletal muscle would be of benefit to diagnosis of BSMA in addition to identification of a mutation of AR gene.

Adult↗

A clinical study of childhood spinal muscular atrophy in Sicily: a review of 75 cases.

The aim of this study is to evaluate 75 patients affected by childhood-onset spinal muscular atrophy (SMA), using the diagnostic criteria and classification recently suggested by the International SMA Collaboration Consortium. Sex predominance, age of onset, clinical evaluation and other relevant clinical data of the disease are reported. These findings, as well as the role of the EMG and muscle biopsy as diagnostic tools, are discussed. The study suggests that the frequency of SMA in some areas of Sicily is high, possibly correlating with a relatively high gene frequency.

Age of Onset↗

[Genetic, histochemical and ultrastructural study of a family with peculiar clinical expression of spinal muscular atrophy. Importance of biopsy examination in the detection of heterozygotes].

A clinical, histologic and ultrastructural study of a woman suffering for a slight form of spinal muscular atrophy and his heterozygotic husband is reported. The woman is daughter of kindred and her brothers have variable clinical manifestation of the disease. Therefore the genetic theory of the "three allels" is emphasized. The presence of histochemical changes in the muscular biopsy of the husband proposes the problem of the existence of tests for the heterozygosis in this disease.

Adult↗

Epidemiology of spinal muscular atrophies in a sample of the Italian population.

In the course of an epidemiological survey in four provinces of Veneto (northeastern Italy) 67 spinal muscular atrophy (SMA) cases (types I, II and III) were recorded. The survey spanned the period 1960-1983 and involved 859,891 consecutive live-born infants in a population of 2,635,800 inhabitants. The overall prevalence at birth for SMA types I, II and III was 7.8/100,000 live births. Type I alone accounted for 4.1/100,000 live births. If the hypothesis that SMA types I, II and III are clinical manifestations of allelic mutations is assumed, the mutation rate would be about 70 x 10(-6) and the frequency of the heterozygotes 1 in 57.

Female↗

International collaborative study of the spinal muscular atrophies. Part 2. Analysis of genetic data.

Most of the cases in the present study are of the juvenile onset, proximal form of spinal muscular atrophy. The results of the study indicate that the majority of these cases are due to one or more autosomal recessive genes, with very few being inherited as a dominant trait. Affected individuals very widely in the severity of the disease. When 2 or more sibs are affected, they tend to be similar as regards severity, but there are a substantial number of sibships in which this is not so. The data are consistent with either a single gene, with a wide range of expressivity due to the effects of other genes and/or environmental influences, or 2 or more genes, but with considerable overlap in their expression.

Adolescent↗

The lateral corticospinal tract and spinal ventral horn in X-linked recessive spinal and bulbar muscular atrophy: a quantitative study.

A quantitative study was performed on spinal cord lesions in seven patients with X-linked recessive spinal and bulbar muscular atrophy. The myelinated fiber density of the lateral corticospinal tracts at the T7 cord level was well preserved for both large and small myelinated fibers. On the other hand, neurons in the L4 ventral horn were markedly depleted; marked loss was noted of the large alpha and medium-sized gamma motor neurons located in the lateral and medial nuclei as well as the small neurons in the intermediate zones of the ventral horn. These results suggest that myelinated fiber density and fiber-size distribution in the corticospinal tract are well preserved and that neuronal loss in the ventral horns is not restricted to alpha and gamma motoneurons but also involves small interneurons.

Aged↗

Biphasic intra-abdominal desmoplastic small cell tumor in a patient with proximal spinal muscular atrophy.

A case is reported of intra-abdominal desmoplastic small cell tumor (IDSCT) with biphasic histologic features in a patient with proximal spinal muscular atrophy. The tumor was composed of small epithelial cell nests with spindle cell sarcomatous areas. Both areas were surrounded by a desmoplastic stroma. Immunohistochemical studies revealed reactivity for low molecular weight cytokeratin, epithelial membrane antigen, vimentin, desmin and Leu-7 in both areas. Electron microscopic examination demonstrated paranuclear aggregates of intermediate filaments, zonula adherens and basement membrane-like material in the epithelial cells, while spindle cells in the tumor had fewer intracytoplasmic organelles. However, intermediate or transitional forms of both types of tumor cells were frequently observed. Although IDSCT are known to express multi-phenotypes immunohistochemically, attention should be paid to the broad spectrum of cell morphology in these tumors.

Adult↗

[Genetic diagnosis and prenatal diagnosis of spinal muscular atrophy by restriction endonucleases digestion of PCR product].

OBJECTIVE: To establish an efficient and rapid method for genetic diagnosis and prenatal diagnosis of spinal muscular atrophy (SMA). METHODS: 11 SMA patients were detected for the deletion and mutation in the survival motor neuron (SMN) gene by restriction endonucleases digestion of PCR products based on the difference between the two homologous copies of SMN. Linkage analysis was performed using four (CA) n repeats. RESULTS: Both eon 7 and exon 8 were deleted in 10 patients. Only exon 7 deletion was found in one patient. Prenatal diagnosis of four SMA pedigrees was performed by restriction endonucleases digestion. SMN gene fragments of three fetuses were different from those of probands, and the SMN gene fragments of one fetus was the same as those of proband. CONCLUSION: Restriction endonucleases digestion of PCR products is an efficient and rapid method for diagnosis of SMA.

Cyclic AMP Response Element-Binding Protein↗

SMN, the product of the spinal muscular atrophy gene, binds preferentially to dimethylarginine-containing protein targets.

The survival of motor neurons protein (SMN), the product of the neurodegenerative disease spinal muscular atrophy (SMA) gene, functions as an assembly factor for snRNPs and likely other RNPs. SMN binds the arginine- and glycine-rich (RG) domains of the snRNP proteins SmD1 and SmD3. Specific arginines in these domains are modified to dimethylarginines, a common modification of unknown function. We show that SMN binds preferentially to the dimethylarginine-modified RG domains of SmD1 and SmD3. The binding of other SMN-interacting proteins is also strongly enhanced by methylation. Thus, methylation of arginines is a novel mechanism to promote specific protein-protein interactions and appears to be key to generating high-affinity SMN substrates. It is reasonable to expect that protein hypomethylation may contribute to the severity of SMA.

Amino Acid Sequence↗

A YAC contig of the region containing the spinal muscular atrophy gene (SMA): identification of an unstable region.

We report a 3.0-Mb YAC contig of the region 5q11.2-q13.3, which is where the spinal muscular atrophy gene has been localized. Three total genomic YAC libraries were screened by the polymerase chain reaction (PCR), and 45 YACs were recovered. These YACs were characterized for sequence tag site (STS) content, and overlaps were confirmed by vectorette PCR. Of the 45 YACs, 20 were isolated with the polymorphic marker CATT-1, which demonstrates significant allelic association with the SMA gene and maps within the 850-kb interval defined by the markers D5S557 and D5S823. Haplotyping of these YACs and their mother cell line indicates that the majority of YACs from this region contain deletions. Furthermore, a 1.9-Mb CATT-1 YAC that was negative for MAP1B and D5S435 and nonchimeric by FISH analysis provides a minimum distance between MAP1B and D5S435.

Base Sequence↗

Rapid detection of single nucleotide polymorphisms associated with spinal muscular atrophy by use of a reusable fibre-optic biosensor.

Rapid (<2 min) and quantitative genotyping for single nucleotide polymorphisms (SNPs) associated with spinal muscular atrophy was done using a reusable (approximately 80 cycles of application) fibre-optic biosensor over a clinically relevant range (0-4 gene copies). Sensors were functionalized with oligonucleotide probes immobilized at high density (approximately 7 pmol/cm2) to impart enhanced selectivity for SNP discrimination and used in a total internal reflection fluorescence detection motif to detect 202 bp PCR amplicons from patient samples. Real-time detection may be done over a range of ionic strength conditions (0.1-1.0 M) without stringency rinsing to remove non-selectively bound materials and without loss of selectivity, permitting a means for facile sample preparation. By using the time-derivative of fluorescence intensity as the analytical parameter, linearity of response may be maintained while allowing for significant reductions in analysis time (10-100-fold), permitting for the completion of measurements in under 1 min.

Biosensing Techniques↗

Neurologic course, endocrine dysfunction and triplet repeat size in spinal bulbar muscular atrophy.

OBJECTIVE: To study the role of diabetes, gynecomastia and CAG triplet repeat size as disease modifying factors of neurologic expression in spinal bulbar muscular atrophy (SBMA, Kennedy's disease). METHODS: Twenty unrelated SBMA patients with confirmatory genetic testing were reviewed. Patterns of neurologic involvement were assessed (e.g. bulbar, asymmetric, proximal, distal, motor and sensory). Slopes of disease progression were calculated from serial quantified neurologic examinations. Patterns of neurologic involvement and course were correlated to the presence of diabetes, gynecomastia and triplet repeat size. RESULTS: Diabetes or glucose impairment occurred in nine and 11 had gynecomastia. Patterns of neurologic involvement and rates of progression did not correlate with these endocrine diseases or triplet repeat sizes. Correlation was seen between number of CAG repeats and age of onset weakness (r = -0.53, r2 = 29%, p = 0.01). CONCLUSIONS: The specific neurotoxic effect of expanded CAGs appears limited to age of onset weakness in SBMA. Although significant, only 29% of the variability in onset age could be accounted for by polyglutamine size suggesting the importance of other unidentified factors. In this series diabetes or glucose impairment was more common than previously reported and, like gynecomastia, did not correlate with size of triplet repeats, severity or patterns of neurologic involvement. Modifying factors other than diabetes, gynecomastia or triplet repeat size are suggested in disease expression.

Adult↗

Muscle strength and motor function in children and adolescents with spinal muscular atrophy II and III.

The aim of this study was to quantify isometric muscle strength and motor function in children and adolescents with spinal muscular atrophy (SMA) and to analyse the impact of reduced muscle strength on motor function. Six children and adolescents with SMA II and eight with SMA IlI were assessed regarding isometric muscle strength and motor function. Isometric muscle strength was tested with a myometer and the values obtained were compared with normative data. Motor function was videotaped and 20 movements were scored according to a three-point scale. All of the assessed children and adolescents with SMA II and SMA III showed reduced muscle strength, but there were great differences within the group. The typical pattern of muscle weakness in SMA, with proximal weakness greater than distal and the lower limbs more affected than the upper, was also seen in these children. The muscle weakness affected motor function in all assessed children. Walking, transfer from lying or sitting to the standing position and stair-climbing were possible in some of the children, despite marked reduction of muscle strength. The study increases our knowledge concerning the degree of muscle weakness in children with SMA and the impact of muscle weakness on motor function. The results increase our possibilities of understanding the prerequisites for everyday life in these children and planning therapeutic interventions. Repeated assessments with the methods used in this study may be used to monitor the course of the disease and to evaluate the efficacy of treatment.

Activities of Daily Living↗