Hi everyone,
I have finally received my Whole Genome Sequencing (WGS) results a few days ago. It is a lot of information, and I have to take the time to analyze all this, which will take months. However, I already have found some significant SNPs ( Single Nucleotides Permutations) that are explaining parts of my POIS.
I will share more in the coming months, but for now, I can share the more significant finding I have done so far: I have 2 SNPs in the CACNA1S gene that are
linked in ClinVar ( a database of SNPs) to a channelopathy called Hypokalemic Periodic Paralysis ( HypoKPP), Type 1. I already suspected that I had a form of HypoKPP. However, my two SNPs,
rs3850625 (Arg1539Cys) and rs12742169 (Leu458His), are not the more usual ones in HypoKPP, so even in this rare disease, I am a less frequent sub-type.
For me, I do not have downright "paralysis", but lethargy, fatigue, and muscle weakness, linked to abnormal potassium levels. A particularity of my presentation is that it takes days to recover. The more frequent presentation is that the person is totally paralyzed for some muscles or even the whole body, for 20 minutes to a few hours. But like POIS, this rare disease has many different presentations, almost unique in each patient.
(P.S. : in my case, both of my CACNA1S SNPs are heterozygote, meaning I have 1 defective version and one usual version on each. However, most HypoKPP mutations are autosomal dominant ( see
https://pubmed.ncbi.nlm.nih.gov/34290819/ ) , meaning that only one defective gene in the pair is enough to have symptoms, although usually less severe. That would explain why I do not have full paralysis, but weakness and extreme fatigue ( I am able to move, but it's a lot more demanding than usual, felt like extreme fatigue )
A current trigger for the attack of PP is exercise or excitement followed by a rest period. It fits both sexual activity and sport, my two main triggers. It also explains the delay... my symptoms set in after some rest, not instantly.
I already knew that potassium was good for my POIS, and as you may know, it is part of my pre-pack. I also take potassium after sport - I have found some years ago that it was helping me recover faster. However, I was unsure about what type of Periodic Paralysis I have before seeing it in my genetic results.
Be aware that there is a sister channelopathy, with similar symptoms, that is called Hyperkalemic Periodic Paralysis, so taking potassium, in this case, will worsen the symptoms. So, unless you have your genome results or have a clear diagnosis with a neurologist, potassium is not to be tried, because potassium at high doses can trigger fatal arrhythmia ( a heart problem) ! Hopefully, HypoKPP Type 1, my type, does not come with myotonia ( muscles stiffness, cramps, spasms). Another gene is related to this type
I have other SNPs that are significant and may contribute to my POIS, like 3 SNPs contributing to low vitamin B12, and another to ammonia elimination being reduced. Many problems in my genes...but that, I already knew.
If you have a POIS similar to mine, that is, with no cognitive symptoms ( no brain fog, no memory problems, no reduced cognitive abilities during POIS), and have POIS-like symptoms after sport/exercise, and other frequent triggers for other people having PP ( but no me) like cold, eating food with high carb/sugars content, hign salt/sodium intake, and stress, you may take a look at the different types of Periodic Paralysis and see a specialist, or have your genome sequenced, and see if this is relevant for you
So, I think having your whole genome sequencing done can be a very good idea if you are motivated to learn how to dig into it and find some needles in the haystack. There are great tools now to do it, and sometimes later I will write on the current methods I use to search in my WGS, if anyone is interested. Also, cost are getting lower and lower. I got my whole genome sequencing ( yes, whole genome, not only 1% of it like with 23andme or myHeritage ) for $299, and paid for a lifetime subscription to their reports database, a total of $499 I think. So far, worth it a lot. I had it done with Nebula Genomics ( good service, but expect 20 to 24 weeks before getting back your results, not the 8 weeks advertised). Also, I have uploaded my results to sequencing.com for free, and they provide a lot of free tools to search and explore your genome, and some very useful tools at very low cost, like the Genome Explorer Plus, helping you figure out with less work which of your numerous SNPs could be more interesting to analyze. However, with any method you choose, be prepared to do a lot of work and searching, or else, pay a genetic counselor to do it for you.
For more information on HypoKPP and other forms of Periodic Paralysis, see
https://periodicparalysis.org/what-is-periodic-paralysis-2/ and
https://rarediseases.info.nih.gov/diseases/6729/hypokalemic-periodic-paralysis