Haplotyping in patients with genetically proven Myotonic Dystrophy type 2

Our research CMO nr. 2007/176 showed that the frequency of autoimmune diseases
(21% vs 2%) and the frequency of autoantibodies (25% vs 2%) were both
significantly (p<0.01) higher in DM2 patients compared to DM1 patients. Data on
DM1 patients were comparable with those of the general population. In a
follow-up study we will investigate the possible underlying mechanism of this
association. In the 3q21.3 region of the DM2 mutation, an interesting set of
genes for autoimmune diseases is known, especially in the CD80/CD86 domain.
Different polymorfisms in CD80 and CD86 seem to be associated with t-cel
mediated autoimmune diseases or comparable clinic such as sensitivity for
infections or a higher chance of acute rejection after organ transplantations,
although results seem as well to be conflicting.

In this study we want to investigate the CD80/CD86 region whether polymorfism
in the 3q21 region of the DM2 population are associated with a high prevalence
of autoimmune diseases. If this is indeed the case, this will help our insight
in the CD80/CD86 region about the rise of autoimmune diseases.

To answer the above question we want to investigate the genetic variation in
the 3q21.3 region. We will start haplotyping in the this region. For this
research, we will use the DNA of genetically diagnosed DM2 patients in the
Netherlands since 2010 (n=35). In this study the material will mainly be:
- lifematerial that was collected in connection with another goal (than
scientific research) and that is concerned. It comes from DNA diagnostic
resulting from the diagnosis DM2. Thus no in general, additional blood
punctures will have to be performed.
- In a maximum of 5 cases a new bloodpuncture will have to take place, namely
because the patient chooses to have a new venaprick above sending her
DNA-material from the UMCU (University Medical Center Utrecht) to the
Radboudumc.

The only risk is a single venaprick.