Ashley:

You might find it helpful to request the reports and know exactly which mutations you have. Sometimes studies are done on specific mutations that might have future implications for treatments and some may have been done on yours.

As for passing it on, there are two primary forms of chloride channel myotonia. Becker MC, which is recessive, and Thomsen MC, which is dominant.

There is also an overlapping area where some mutations that were previously thought to be recessive, sometimes display a dominant inheritance in some families.

Let's assume though that you either have a dominant, or recessive form.

We typically inherit genes in pairs called alleles. We inherit one of the genes in the pair from our mother, and the other one in the pair from our father. The genes may be identical or may be slightly different variations of each other, but the purpose is to have a backup if one of them is different enough that it doesn't work properly.

In recessive mutations, like mutations that cause Becker MC, the affected individual inherited two mutated versions of the CLCN1 gene, and neither of them work properly.

That means...

1. Both of their parents were carriers...meaning they each had a good CLCN1 gene and a bad CLCN1 gene and the affected child inherited the bad one from both of them. The odds of two carriers having an affected child are 25%.

2. One parent was a carrier and one parent was affected (someone with Becker MC just happened to have children with someone who was not affected but was a carrier). The odds of their child being affected is 50% because there is a 100% chance they will inherited a bad gene from the affected parent, and a 50% chance they will inherit the bad gene from the parent who is a carrier, and they need two bad genes to have the disorder.

3. Both parents are affected, meaning both of the parent's CLCN1 gene pairs consist only of bad CLCN1 genes. The odds of passing the disorder on to their child is technically 100%. This tends to only happen in small isolated populations or populations where it's tradition to marry cousins or other relatives.

In the case of the dominant Thomsen MC, a person only needs one bad gene in the pair. The good gene can't compensate for the bad one for some reason. So if one parent has Thomsen MC and the other parent does not, there is a 50% chance their child will have it because there is a 100% chance the child will inherit a good gene from the non-affected parent and a 50% chance the child will inherit the bad gene from the affected parent.

So generally speaking they say if you have Thomsen MC, there is a 50% chance you will have a child who has it, and if you have Becker MC there is a 25% chance your child will have it.

MC can be a bit funny though and in reality, there is a very very very small chance that someone with Becker MC will pass it on to their children even if the other parent is not a carrier, and there is a reasonable chance that someone with Thomsen MC will have children who do not display symptoms even if they have the gene.

Type of Myotonia: Becker

Country: USA

Thanks for the breakdown(I wish you would have taught my biology class because that was way easier to understand lol)I didn't marry my cousin, ha ha so hopefully my son won't get it. I just know how much it stunk when I was little and I didn't want to play sports because it was so embarrassing to not be able to start running like everyone else. It would kill me to know that my son felt this way one day. I'll get my reports from the doc (and probably ask you more questions )Thanks for taking the time to chat with me.

Country: US

Ashley,

Sorry I didn't get to welcome you sooner! I was at a conference last week with no access to the forum so I'm catching up.

Jenna gave you some great information and you can also look at some of the resources on the main website (click on "return to website" above. The letter for school staff has a lot of basic information about MC and there is a page about the diet that I have used most of my life.

I have tried many supplements over the years and out of all the different vitamins, minerals, herbs and amino acids I have found two things that do seem to be very helpful. One is the amino acid Acetyl-L-Carnitine, and the other is the herb Licorice Root. I take 500 mg of the carnitine per day and one capsule of licorice root powder (I use Nature's Way brand).

The carnitine seems to increase ATP or at least spare it so that our muscle cells aren't damaged as easily, and the licorice root causes excess potassium to be lost in the urine. The only contraindication for that would be high blood pressure. I have never used any medications for the myotonia, but before I started the diet I was so stiff all the time I was always getting hurt and was even afraid to answer the phone at times because I sounded drunk. The goal is keeping insulin levels stable so that you don't cause excess adrenalin output. Also sugar uses up phosphorus, and we have a very high demand because of the constant firing of the muscles.

If you can email me a copy of your DNA test results I can look up the specific mutation or mutations and tell you more.

Jan

Type of Myotonia: Thomsen's

Country: USA