Sunday, 29 April 2012

Dupuytren's and Ledderhose family history


So today I have the pleasure of looking at a family tree that Ellen's Mum and I have put together, I have made it anonymous but that doesn't mean we can't discuss it. So as you can see from the above tree only o is Ledderhose only with one possibly case seen in C. This goes to show that even in a family here with about 50 people shown we can only see 1 case where there is an individual with Ledderhose only and this was initiated by a massive trauma event. In total there are 10 cases of Dupuytren's and many of the people are under 50 years old so who knows how this would look if seen in 20 or 30 years times. There were however 4 people with both Ledderhose and Dupuytren's and interestingly 3 of these cases appear in the 9 and A lineage. 

9 and A

So I am going to start by looking at 9 and A as this part of the tree has a very high incidence of the disease. Here we have data on 9 individuals including 9 and A and 6 of them have these diseases in one form or another. So this part of the tree has 66% prevalence and you have to wonder what the odds are for (a) seeing as both A and P are people that are not blood relatives to 1 and 2 and they are the only others in this lineage that do not have the disease. I think this is really interesting as it suggests that there is a strong genetic link that has been passed down by 9 to M, N and O and this has in turn been passed down to b and c. Of course I am not aware of all factors but as far as I am aware there is no diabetes in this tree but they may smoke or drink excessive amounts of alcohol which could contribute towards this.

F and G and the rest of the tree

Ok so this part of the tree makes me less concerned about the genetic element. Ok so take out 9 and A and that part of the tree and suddenly you are down to 7 confirmed cases of Dupuytren's or Ledderhose and one of these comes from outside of the 1+2 blood line and that is in about 40 cases so down to less than a 25% prevalence compared to the 66% is quite low. I think that the interesting thing about the F and G line is that it skips a couple of generations and then only appears in o after trauma and o also has a grandparent from a different lineage that has Dupuytren's so it could have come from their rather than any genetics link passed down from 1 and 2. 

Summary:

What this tree seems to show is exactly what is mentioned in all of the papers and that is that this disease is dominant but has different rates of appearing and maybe requires a trigger so that if you are susceptible to getting the disease you may still need a trigger such as trauma or excessive alcohol to actually cause the disease to show itself.  

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