New lead for myotonic dystrophy

I’ve just come across a new research paper about myotonic dystrophy. Researchers at the University of Valencia in Spain recently identified a new way to block the genetic mutation causing myotonic dystrophy type 1.

Myotonic dystrophy is caused by the inheritance of an expanded piece of repeated DNA. DM1- the most common form of myotonic dystrophy- is caused by the expansion of a repeated section of DNA in a gene called DMPK. A three letter code in this gene is repeated many hundreds of times instead of the usual number which is less than thirty. This repeated section of genetic code interferes with the functions of other proteins in the cell.

It is known that RNA- the carbon copy of DNA which carries genetic messages from the cell nucleus to the rest of the cell in order to build proteins- is key to causing myotonic dystrophy.

The extra repeated section of genetic code in the DMPK gene causes the RNA copy of the gene to get stuck inside the nucleus and grab onto certain other proteins and hold them hostage. This leads to the formation of clumps of RNA and protein in the cell nucleus. The proteins held in these clumps are then unable to perform their normal functions in the cell.

In this new research they used a fruit fly model of myotonic dystrophy to screen a library of small pieces of protein (peptides). They found one promising peptide that stopped the formation of clumps inside the cells of the flies and stopped muscle degeneration. They also tested the peptide in a mouse model of myotonic dystrophy with positive results.

The next step will be to further test this peptide in the laboratory before testing in humans.

The scientific paper was published online July 5, 2011, in Proceedings of the American Academy of Sciences. http://www.pnas.org/content/early/2011/06/27/1018213108.abstract