Genetic mutations on SCN9A gene…
Has anyone had this testing? What is the process to request and what is the procedure like?
I have. It was just a blood test. My neurologist ordered it on a lab slip and it was sent out to be processed.
Jen, thank you for sharing. Once we know if it is primary or secondary are the differences in treatment implications?
Well… If you are positive for the gene then you will know that there is probably not a secondary cause for your symptoms. I am not sure if you were worked up for underlying causes. If they can find an underlying cause they would treat that and hopefully it would help your erythromelalgia. I was negative for SCN9A testing but they cannot find an underlying cause so I am considered idiopathic. (I was shocked b/c I have had symptoms since childhood). I understand that they are looking into other sodium channel gene mutation tests and my neuro said another one will be available shortly!
I too was negative for the gene which I was expecting since I was in my 60s when EM began for me. However my daughter has EM and I have just discovered that I have a neice with undiagnosed facial flaring/burning so it would seem to be inherited. I am part of the Xenon trial and they are indeed looking for other problem genes and they conducted a phone interview with me a few days ago. I am glad they are looking further for the sake of younger generations.
Dearest Stacey (and Royce),
I am so dreadfully sorry you and your family are still struggling to find help for your son.
Testing can be both blood and saliva (DNA sequencing).
Treatments/minimisation tactics to try better manage EM are exactly same regardless of type. Only difference is that Aspirin has been reported to 'work' better in primary familial EM. Also, with secondary EM they can treat the underlying disorder( e.g. lupus), or in case of medication induced, taper the medication. Medication induced EM has good rates of remission once offending medication stopped.People often forget that diet may also trigger- especially histamine laden foods or additives.
3 types of EM are currently known. Primary genetic familial, Primary genetic sporadic(idiopathic), and Secondary to an underlying disorder, medication, injury/surgery has been reported too, but rare. Genetic mutations have been found in those classed as primary sporadic . These were discovered by Xenon's genetic saliva test trial earlier this year- as yet not sure what they mean. These sporadic 's are being labelled and classified so interesting what we will be informed upon dissemination next year.
Regarding EM, no known diagnostic test out there. EM diagnosis is based on clinical presentation and patient history. Tests that may be performed such as small nerve (SFN), thermoregulating(sweat tests), electrophysiological are exclusion of differential diagnoses such as CRPS (Chronic regional pain syndrome)- many conditions mimic EM such as CRPS, RS, burning feet syndrome, diabetic neuropathy. etc. SFN has been found in approx 40% of EM sufferers and considered strongly implicated in EM. However, many EM'ers do not have SFN so this is not an EM diagnostic . Only blood/saliva will pinpoint the SCN9A mutation on Nav 1.7.
Have uploaded an article regarding all the possible blood, radiological work etc.. that may be used to exclude differential diagnoses.
Did Royce's symptoms start with his ADHD medication?
God bless
Hi Mads,
Not sure if you’re still on here, but I’d love to see the article you reference listing the various tests that can exclude other diagnoses. Is it still available somewhere?
Thanks!