Hi RSDMom,

I don't think they have found a really definite gene connection yet, although it is suspected, but then they haven't really looked too hard. I have become quite interested in this topic, along with an interest in all the other conditions which are so similar to RSD/CRPS.

There is an underswell of opinion that thinks it may turn out that RSD is a disease with many subtypes and even subtypes of subtypes.

One of the conditions that interests me is eythromelalgia, which is so similar to RSD that I can't see the difference. I think it quite likely it could be a subtype of RSD (or the other way around?) - I'm no doctor, though, just giving you the benefit of my musings after reading up about it.
Here's a link for erythromelalgia:
http://www.erythromelalgia.org/tea/s...ythromelalgia?

I mention this because with erythromelalgia there is an identified genetic mutation in the gene SCN9A, though not all sufferers have the mutation. Many do, though.

If you haven't asked the docs about it (maybe you already have) I would ask them.

Here is an extract from a recent post of mine:

http://neurotalk.psychcentral.com/sh...ad.php?p=91469

"SCN9A-Related Inherited Erythromelalgia"
http://www.genetests.org/profiles/etha

"SCN9A-related IEM is characterized by recurrent attacks of intense pain, redness, warmth, and swelling involving the feet, and less frequently, the hands [Drenth & Michiels 1994]. Warmth is an essential part of the syndrome. During the attacks, the extremities appear red or purple and may be swollen. Commonly, the attacks occur in the evening or at night and so may not be observed by a physician. The individual may seek medical advice for painful extremities, but neglect to mention the characteristic warmth or redness (especially if limited to the soles of the feet). The symptoms are usually bilateral and symmetric. Within a family, the manifestations of the disorder may vary considerably."

.........Then, interestingly, there are other complications. They found a family of 6 kids in Pakistan with a genetic mutation of the SCN9A gene. They can't feel any pain at all.

"The mutation that takes away pain"
http://www.bioedonline.org/news/news.cfm?art=3002

"The researchers compared DNA samples from the six children and found that they all share a mutation in a gene called SCN9A, which is strongly expressed in nerve cells. They report their results in Nature.
The SCN9A gene encodes a 'sodium channel': one of the structures that allows electrical charge to flow into nerve cells, triggering a signal, the researchers explain. Without this particular type of sodium channel, the brain does not receive any signal that the body has encountered a pain-causing stimulus."

I'm not trying to suggest that your family has this instead of RSD. I'm just pointing you to some research into a condition that is so similar that any research in that area could have consequences for those with RSD and similar conditions.

Whether or not erythro is or isn't a subset of RSD, I have a feeling that the discovery of this gene mutation, both pain-causing and pain blocking, may help to further the understanding of all the other conditions which are so similar....I hope so, anyway.

I wonder what prompts doctors to send a patient for gene-testing? And what are the requirements for qualifying for the test? And are you only tested for the one condition suspected, or is it more general? I don't know....I'll continue my questing, but if anyone does know, please enlighten me.

I doubt if this is all that helpful to you, but it does show that there could be something to hope for down the lines, gene research is still in its infancy.

Has anyone here ever been gene-tested?

Anyway take care,
all the best