Expanding complexity in myotonic dystrophy

✍ Scribed by Patricia Groenen; Bé Wieringa

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 407 KB
• Volume: 20
• Category: Article
• ISSN: 0265-9247
• DOI: 10.1002/(sici)1521-1878(199811)20:11<901::aid-bies5>3.0.co;2-0

✦ Synopsis

Myotonic dystrophy (DM) is a highly variable multisystemic disease belonging to the rather special class of trinucleotide expansion disorders. DM results from dynamic expansion of a perfect (CTG) n repeat situated in a gene-dense region on chromosome 19q. Based on findings in patient materials or cellular and animal models, many mechanisms for the causes and consequences of repeat expansion have been proposed; however, none of them has enjoyed prolonged support. There is now circumstantial evidence that long (CTG) n repeats may affect the expression of any of at least three genes, myotonic dystrophy protein kinase (DMPK), DMR-N9 (gene 59), and a DM-associated homeodomain protein (DMAHP). Furthermore, the new findings suggest that DM is not a simple genedosage or gain-or-loss-of-function disorder but that entirely new pathological pathways at the DNA, RNA, or protein level may play a role in its manifestation.