Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The classical form of congenital muscular dystrophy (CMD) is now classified into merosin-deficient and -positive forms. The merosin (laminin alpha 2) is one of three subunits of a muscle basement membrane protein, laminin. Patients with the merosin-deficient form have generalized muscle weakness and hypotonia from early infancy as seen in FCMD but with no significant central nervous system involvement. The serum creatine kinase (CK) is markedly elevated. Strikingly all patients examined by a CT/ MRI have diffuse white matter abnormalities mimicking leukodystrophy. The gene has been mapped to chromosome 6q2 in the coding region for merosin. Since the responsible gene and protein have not been identified in the merosin-positive form, this CMD is probably a group of heterogeneous diseases. The overall symptoms are mild, approximately 90% of patients learned to walk alone.
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PMID:[Non-Fukuyama type congenital muscular dystrophy--merosin deficient and positive forms]. 943 31

We report on two brothers (the product of first-degree consanguineous marriage; aged 15 and 12 years) who presented with severe hypotonia at birth, proximal muscle weakness associated with delayed motor milestones but normal cognitive function. Investigations (at 4 years of age) revealed mildly elevated serum creatine kinase (CK) levels (300 and 824 IU/l; N < or = 210). Muscle biopsies showed minimal change myopathy, no neurogenic atrophy but remarkable type-1 fibre predominance (up to 85.5%) without fibre-type disproportion. Clinical examination at 12 and 9 years, respectively, showed mild facial weakness and high-arched palate in both patients. The younger sibling also had ptosis but otherwise normal external ocular muscles. They showed symmetric proximal muscle weakness and wasting associated with calf-muscle hypertrophy. They could walk independently. A repeat muscle biopsy showed advanced dystrophic changes in the younger patient at the age of 10 years. Virtually all the remaining fibres were type 1. Immunohistochemistry revealed normal expression of the dystrophin-glycoprotein complex (DGC), including dystrophin, beta-dystroglycan, alpha-(adhalin), beta-, gamma-, and delta-sarcoglycan, laminin-alpha2 chain (merosin) and syntrophin. Mild dystrophic features and type-1 fibre predominance (92.5%) were seen in the biopsy of the older patient, whereas immunohistochemistry showed normal expression of the DGC. Both cases also showed clear expression of integrin alpha7 at the muscle fibre surface and in the blood vessels. Three years later, they could still walk, but with difficulty, and the older brother showed enlargement of the tongue and echocardiographic features of left ventricular dilated cardiomyopathy.
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PMID:A novel form of familial congenital muscular dystrophy in two adolescents. 1002 46

We report a patient with congenital muscular dystrophy (CMD), developmental brain defects, and peripheral neuropathy. Marked hypotonia and plagiocephaly were noted at birth. Failure to thrive, generalized muscle weakness and wasting, absent deep tendon reflexes, partial seizures, and secondary microcephaly developed. Brain MRI showed a large area of cortical dysplasia, a thin but complete corpus callosum, and diffuse ventriculomegaly. Nerve conduction velocities were slow and creatine kinase levels only mildly elevated. Muscle biopsy showed dystrophic features with normal merosin, sarcoglycan, and dystrophin immunostaining. The Japanese Fukuyama CMD founder mutation was not detected. This is the first report of a patient with merosin-positive CMD, cobblestone lissencephaly, and demyelinating peripheral neuropathy.
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PMID:Congenital muscular dystrophy with central and peripheral nervous system involvement in a Belgian patient. 1039 53

A 3-month-old female baby was diagnosed as having Walker-Warburg syndrome (WWS), based on the following clinical findings: type II lissencephaly associated with marked ventricular dilatation, cerebellar malformation, retinal malformation, elevated serum creatine kinase level and abnormal muscle CT findings. She was a product of parents with consanguineous marriage. She presented with severe hypotonia and profound psychomotor retardation since birth. She developed infantile spasms at 8 months of age, and vitamin B6 was very effective. A genetic analysis revealed the absence of the founder haplotype commonly seen in Fukuyama-type congenital muscular dystrophy (FCMD), suggesting that the WWS gene is not always identical to the FCMD gene. When she was examined at the age of 4 years, she had no apparent further psychomotor development. Her clinical symptoms were more severe than those of the typical FCMD.
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PMID:[A patient of Walker-Warburg syndrome with a haplotype different from that in Fukuyama-type congenital muscular dystrophy]. 1048 70

Merosin-deficient congenital muscular dystrophy is an autosomal recessive neuromuscular disorder caused by partial or total absence of laminin-2 (merosin) in the skeletal muscle. Affected children have severe weakness, hypotonia at birth, high creatine kinase (CK) levels (more than 10 times normal) and are not able to walk or stand unsupported. Linkage and mutation analysis demonstrated that the gene encoding for the laminin-alpha2 chain, mapped on chromosome 6q22-23, is invariably responsible for this form of congenital muscular dystrophy. We investigated the pattern of inheritance of the haplotypes associated with the mutated allele in 29 informative merosin-deficient families, using tightly linked informative polymorphic microsatellite markers. This allowed us to identify heterozygous individuals from normal homozygotes, who are clinically, pathologically and biochemically indistinguishable. By linkage analysis, we found a statistically significant increase in the number of heterozygous individuals carrying either the paternal or the maternal haplotypes associated with the mutated allele. This could suggest a selection in favour of the alleles carrying mutations at the laminin alpha2-chain locus.
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PMID:Is there selection in favour of heterozygotes in families with merosin-deficient congenital muscular dystrophy? 1054 97

We investigated two children who presented with delayed motor milestones. The first was a girl who was referred at 20 months because of developmental delay. She walked at 28 months and currently, aged 5 years, is independently mobile but has difficulty rising from the floor or going upstairs. The second was also a girl who presented at 6 weeks of age with hypotonia. Her motor milestones were delayed and she walked at the age of 2 years and 8 months and is currently independently mobile at the age of 3 years. Serum creatine kinase was elevated and a muscle biopsy showed dystrophic changes in both children. Immunohistochemistry of the laminin alpha2 chain of merosin was very similar in both cases: using a C-terminal antibody that recognizes an 80 kDa fragment, there was a mild reduction in expression on most fibres, while the staining with another antibody that recognizes a 300 kDa fragment showed a very marked reduction. Mutational analysis of the laminin alpha2 chain gene in the first patient showed that one of the two alleles had a de novo single nucleotide deletion at position 5702, causing a frameshift. In the other allele, we identified two point mutations present in cis; one was a G-->C transition at position +5 while the second was a T-->C transition at position +6 of the conserved donor splicing consensus sequence of introns 37 and 63, respectively. Transcription analysis of the corresponding cDNA region did not show any alternative splicing occurring as a result of these splice site mutations. Therefore, these mutations probably affect the splicing efficiency. Interestingly, the second child carried in both alleles the same two splicing consensus sequence mutations found in cis in the first patient. Our data provide further evidence that mutations in the laminin alpha2 chain gene are responsible not only for the severe form of congenital muscular dystrophy with onset at birth, but also for milder phenotypes, with later onset, in which the synthesis of a partially functional protein, or of a normal protein but in reduced quantity, is possible. The finding that these two unrelated patients had the same unusual mutation in common might suggest that this is a relatively commonly allele responsible for partial merosin deficiency in the UK.
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PMID:Mutations in the laminin alpha2-chain gene in two children with early-onset muscular dystrophy. 1061 Nov 18

Congenital muscular dystrophy (CMD) is a rare heterogeneous disease found in the oriental population, especially the occidental type of CMD. We report a case of a one-year-old infant who presented with early onset hypotonia, muscular weakness, delayed motor development and normal intelligence. A muscle biopsy revealed dystrophic muscle fibers. A high creatine kinase (CK) level, mostly of the MM type, was also noted. Further study of brain images showed hyperintense lesions in the white matter area. The patient showed the clinical and laboratory findings characteristic of CMD, more likely to be of the occidental type. Further genetic or histopathologic studies, especially merosin investigation, are suggested for improved classification and prognosis prediction.
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PMID:Congenital muscular dystrophy. 1067 31

We report a case of congenital muscular dystrophy with secondary merosin deficiency, structural involvement of the central nervous system and mental retardation in an 8-year-old girl from a consanguineous family. She had early-onset hypotonia, generalized muscle wasting, with weakness especially of the neck muscles, joint contractures, mental retardation and high creatine kinase. Muscle biopsy showed dystrophic changes with partial deficiency of the laminin alpha(2) chain. Cranial magnetic resonance imaging revealed multiple small cysts in the cerebellum, without cerebral cortical dysplasia or white matter changes. The laminin alpha(2) chain (6q2), Fukuyama type congenital muscular dystrophy (9q31-q33) and muscle-eye-brain disease (1p32-p34) loci were all excluded by linkage analysis. We suggest that this case represents a new entity in the nosology of congenital muscular dystrophy.
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PMID:Merosin-deficient congenital muscular dystrophy with mental retardation and cerebellar cysts unlinked to the LAMA2, FCMD and MEB loci. 1105 80

We analyzed three Japanese patients (two boys and a girl) from two families with congenital muscular dystrophy (CMD) and brain involvement. One of the two families had two affected siblings of different sexes. Parental consanguinity was not documented in either family. All patients showed generalized hypotonia and weakness from infancy, delayed psychomotor development, facial muscle involvement, and joint contractures. Serum creatine kinase levels were markedly elevated. The histological change seen on muscle biopsy was characteristic of a dystrophic process, although dystrophin and merosin staining were normal. On MR imaging, cortical dysplasia and cerebral white matter abnormalities were observed. Although these clinical, myopathological and neuroradiological findings were typical of Fukuyama-type CMD (FCMD), full mutational analysis of the fukutin gene revealed neither a 3 kb insertion (Japanese founder mutation) nor point mutations. RT-PCR analysis of RNA isolated from lymphoblasts of a patient revealed normal expression of the FCMD transcript. As classification of CMD should be based on genetic background, our present cases with typical clinical, myopathological and neuroradiological findings of FCMD without mutation of the fukutin gene may represent a new variant (or variants) of CMD that is different from FCMD.
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PMID:A variant of congenital muscular dystrophy. 1175 Oct 21

A 1.5-year-old boy with macrocephaly due to a Dandy-Walker malformation presented with progressive hydrocephalus, extensive muscular hypotonia, transient cholestatic syndrome, extensive coagulation abnormalities and elevated creatine kinase indicating myopathy. Diagnostic work-up indicated a congenital disorder of glycosylation (CDG, formerly carbohydrate deficient glycoprotein syndrome). The serum transferrin pattern obtained by automated isoelectric focusing (IEF) showed an hitherto unreported pattern with strongly elevated tri-, di-, mono- and asialotransferrin bands, increasing in this order together with markedly decreased tetrasialotransferrin. Investigation of two additional glycoproteins, alpha(1)-antitrypsin and alpha(1)-antichymotrypsin, confirmed a generalised defect of glycosylation. All known glycosylation defects could be ruled out by enzymatic analyses in either leukocytes or fibroblasts or by the results obtained by IEF. SDS-electrophoresis demonstrated a marked difference in the molecular weight of transferrin, suggesting the lack of parts or of all oligosaccharide chains. The defect could be delineated to a deficiency of beta-1,4-galactosyltransferase (E.C.2.4.1.38) due to a homozygous insertion (1031 - 1032 insC). Details of the biochemical and molecular findings will be described elsewhere.
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PMID:Congenital disorder of glycosylation IId (CDG-IId) -- a new entity: clinical presentation with Dandy-Walker malformation and myopathy. 1193 Feb 73


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