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Re: Greetings from Spain

Luis"I had the same problem with speech because of My tonge not responding from cold or to much potassium.

Type of Myotonia: Beckers Myotonia

Country: USA

Re: Greetings from Spain

Hello!!

I'm from Spain and I have been diagnosed recently Myotonia of Thomsen

The EMG was positive and DNA analysis confirmed that it had a homozygous mutation of Gly233Val.

regards



Re: Greetings from Spain

Ana, glad you got a definite diagnosis! So you would have the recessive form, Becker's MC. That's always good news for people who have children or who want to have children because the chances of them having symptoms is almost zero, even if they are a carrier of the mutation.

Has your doctor talked to you about medications for myotonia? I don't believe mexiletine is available in Spain. Some of the others used to treat MC would be acetazolamide (Diamox), phenytoin (Dilantin), lamotrigene, flecainide, carbamazepine (my least favorite), and quinine sulfate. Diamox and quinine seem to have the fewest side effects, especially for younger people.

Jan

Type of Myotonia: Thomsen's

Country: US

Re: Greetings from Spain

Hello! No, I have the dominant form, Thomsen MC. My doctor has not put me treatment yet. My doctor has considered more important, that I first saw the medical geneticist. The geneticist will explain me the chances of transmitting the disease to my children and the problems they may have.

The neurologist told me that after visiting the geneticist visit again to see the ability to get treatment.

I do not speak good English, I hope you can understand me. A greeting!

Re: Greetings from Spain

Ana,

Do you have two copies of the same mutation? I can't access my genetic database right now, but if G233V is associated with dominant MC, then both your parents would also have symptoms. (Heterozygous is one, homozygous is two.) Is that the case? I haven't ever heard from anyone who had two dominant mutations, but a few have had one dominant and one recessive. That's pretty rare, too.

Jan

Type of Myotonia: Thomsen's

Country: US

Re: Greetings from Spain

Hi Jan,

In the results of my genetic test is written: it has been identified by sequencing the presence of pathogenic homozygous mutation c.698g>T in the gene CLCN1. This change is a "missense" mutation leading to the replacement of glycine by vanila at position 233: p.Gly233Val (p.G233V)

I do not really understand what it means, but my parents did not have any symptom, however, I have symptoms since childhood.

Re: Greetings from Spain

Ana, did you have an EMG showing myotonic discharges? Also, do you know exactly what type of DNA testing was ordered? In the US the gene is usually specified (like CLCN1), but perhaps your lab did a profile looking at several genes.

I don't see that genetic mutation listed in the database for myotonia congenita. However it is a variant associated with Limb Girdle Muscular Dystrophy Type 2A which is on a different gene (CAPN3).

Here are a few of references about it:

LGMD2A Variant Listing

MUSCULAR DYSTROPHY, LIMB-GIRDLE, TYPE 2A

Coalition to Cure Calpain 3

The symptoms could be quite similar earlier in life. I don't know if the lab made a mistake listing the gene or the variant, or if it is a variant for myotonia congenita that hasn't been published yet (very unlikely that it would have exactly the same notation as the LGMD2A variant).

I would suggest contacting the lab or having your geneticist contact them to review the results and make sure they were reported correctly. It's not the first time I have seen misreported test results, so it's worth confirming because they are two entirely different conditions.

If it does turn out to be Limb Girdle MD, there is a doctor in San Sebastian who specializes in LGMD:

Lorea Blazquez
Hospital Donostia
lblazquez@chdo.osakidetza.net

Please let me know what you find out -

Jan

Type of Myotonia: Thomsen's

Country: US

Re: Greetings from Spain

Yes, I have myotonic discharges an EMG.
My DNA testing is, Myotonia congenita: CLCN1 gene sequencing.

I have sent you an email with the article.

thanks for the info

Type of Myotonia: Thomsen's