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)

Severe forms of myotubular myopathy (MTM) and congenital myotonic dystrophy type 1 (CDM), both present as floppy infants with hypotonia, respiratory failure and bulbar insufficiency. Muscle biopsy is often performed as part of the diagnostic process, but these two disorders share very similar histopathological features. It is well documented that CDM muscle has nuclear foci that contain muscleblind-like 1 (MBNL1) protein. In muscle biopsies from eight neonates showing central nuclei, MBNL1 immunolocalisation identified discrete, intensely stained foci in three cases that were subsequently confirmed as CDM by DNA analysis. In the five remaining non-CDM patients and two controls, MBNL1 staining was heterogeneous in nuclei, not as foci. MBNL1 staining patterns in CDM were easily distinguishable from MTM. We suggest that in cases of hypotonia with suspected CDM or MTM, when biopsy has been taken, sections should additionally be stained for MBNL1 to provide a rapid indication of a CDM diagnosis.
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PMID:A rapid immunohistochemical test to distinguish congenital myotonic dystrophy from X-linked myotubular myopathy. 2211 58

Myotonic dystrophy type 1 (DM1) is an autosomal dominant disorder with variable expression. DM1 results from a trinucleotide expansion in the 3' untranslated region or the gene for myotonic dystrophy protein kinase (DMPK). Severity tends to increase and it shows a younger onset age with vertical transmission, a phenomenon known as anticipation. Congenital myotonic dystrophy (CDM) is classified as the most severe form of DM1, and its phenotype, with severe hypotonia, neonatal respiratory distress and feeding difficulties, is completely different from that of adult-onset type. Involvement of respiratory muscles may be the major cause of mortality in affected infants. Facial weakness with a tented upper lip is often recognized. If infants survive the neonatal period, muscle involvement symptoms gradually improve and most children do not require respiratory support or tube feeding. As CDM patients grow older, mental retardation or a developmental disorder becomes prominent. Furthermore, the main problems in childhood-onset DM, with an onset age under 10 years, are developmental disorders or learning disabilities, rather than muscle symptoms. Early meticulous support and cooperation with teachers are necessary. Medications such as methylphenidate may be helpful in DM1 children with attention deficit/hyperactivity disorder.
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PMID:[Clinical features and care of patients with congenital and childhood-onset myotonic dystrophy]. 2319 84