Document Detail


Myotonic dystrophy: molecular and cellular consequences of expanded DNA repeats are elusive.
MedLine Citation:
PMID:  9211188     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The mutation in the myotonic dystrophy (DM) gene is an expansion in a triplet (CTG) repeat in the 3' untranslated region of a novel gene that partially encodes a serine-threonine protein kinase (DMPK), with closest sequence homology to a small subgroup of protein kinases involved in the control of proliferation and cell shape. Expansion of the repeat correlates reasonably well with disease severity and offers a plausible molecular explanation for the previously contentious issue of anticipation. There is considerable heterogeneity in CTG expansion size in different tissues of affected individuals. The consensus of data from many laboratories indicates that DMPK mRNA is most probably downregulated as a consequence of the repeat expansion. Two polypeptides (68/78 kDa) have been shown to be absent in mouse knockout mutants and therefore can be considered as bona fide gene products. Previous data suggesting that 52-55 kDa polypeptides were likely candidates, have been firmly ruled out at the same time. Further results from studies of knockout and overexpressing transgenic mice indicate that neither simple loss nor gain of DMPK expression is sufficient to account for the DM clinical phenotype. One of the most pressing questions now being addressed is how expansion of the CTG repeat within the DMPK gene affects gene expression, not only of DMPK, but of all genes at the 19q13.3 locus: is DMPK actually responsible for the clinical phenotype seen in DM? The identification of both immediate upstream and downstream human genes (59 and DMRHP, respectively) has been an important first step to answering these questions. Only when these matters have been dealt with can one reasonably expect to start to delineate the different metabolic and signalling pathways responsible for the diverse phenotypes that make up the complex clinical picture of DM.
Authors:
P N Strong; B S Brewster
Related Documents :
7605908 - Acetylcholine esterase and peripherin mrna level decrease in wobbler mouse.
10751678 - Brain dystrophin, neurogenetics and mental retardation.
19472918 - Candidate-gene testing for orphan limb-girdle muscular dystrophies.
7853378 - High ctg repeat number in nodular thyroid tissue from a myotonic dystrophy patient.
17036308 - Incorporating genetic analyses into birth defects cluster investigations: strategies fo...
8138168 - Evidence for the partial dominance of viability genes contributing to inbreeding depres...
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Journal of inherited metabolic disease     Volume:  20     ISSN:  0141-8955     ISO Abbreviation:  J. Inherit. Metab. Dis.     Publication Date:  1997 Jun 
Date Detail:
Created Date:  1997-09-09     Completed Date:  1997-09-09     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7910918     Medline TA:  J Inherit Metab Dis     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  159-70     Citation Subset:  IM    
Affiliation:
Department of Paediatrics and Neonatal Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Gene Expression
Humans
Mutation
Myotonic Dystrophy / genetics*
Protein-Serine-Threonine Kinases / genetics,  physiology
Trinucleotide Repeats*
Chemical
Reg. No./Substance:
EC 2.7.11.1/Protein-Serine-Threonine Kinases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Kennedy disease.
Next Document:  The recognition of Lesch-Nyhan syndrome as an inborn error of purine metabolism.