Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012872 (DNA marker)
 929 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Proximal spinal muscular atrophies represent the second most common fatal, autosomal recessive disorder after cystic fibrosis. The childhood form is classically subdivided into three groups: acute Werdnig-Hoffmann (type I), intermediate Werdnig-Hoffmann disease (type II) and Kugelberg-Welander disease (type III). These different clinical forms have previously been attributed to either genetic heterogeneity or variable expression of different mutations at the same locus. Research has been hindered because the underlying biochemical defect is unknown, and there are insufficient large pedigrees with the most common and severe form (type I) available for study. Therefore, we have undertaken a genetic linkage analysis of the chronic forms of the disease (types II and III) as an initial step towards the ultimate goal of characterizing the gene(s) responsible for all three types. We report here the assignment of the locus for the chronic forms to the long arm of chromosome 5 (5q12-q14), with the anonymous DNA marker D5S39, in 24 multiplex families of distinct ethnic origin. Furthermore, no evidence for genetic heterogeneity was found for types II and III in our study, suggesting that these two forms are allelic disorders.
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PMID:Gene for chronic proximal spinal muscular atrophies maps to chromosome 5q. 197 Apr 20

Linkage studies with 9 highly informative DNA markers on the long arm of chromosome 5 were performed in 12 multiplex families (29 patients) with spinal muscular atrophy (SMA) from The Netherlands. The results of the linkage analysis were compatible with localization of a major SMA gene in the chromosomal region 5q12-13. By minimum recombinant analysis the most likely position of the SMA locus was between loci D5S6/D5S125 and D5S112/MAP1B, which is in agreement with several linkage studies from other countries. In four families, however, more than one crossover between SMA and a flanking DNA marker appeared, and in one family the observed hybridization phenotype for the markers closely flanking the SMA locus was identical for an unaffected individual and for his two affected sibs with SMA type III. For this latter family, among several explanations the most likely are either the presence of a double crossover or linkage heterogeneity.
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PMID:Linkage and apparent heterogeneity in proximal spinal muscular atrophies. 826 30