Genetics and MG
 

My daughter is a teenager and my neuro believes she has MG now. She has double vision, weakness in her arms/legs/hands, jaw fatigue, and ptosis in both eyes.

So far she is seronegative (like me) which they expected but her pulmonary function tests show severe weakness of the diaphragm in PI max and PE max which I believe is the same as maximum inspiratory/expiratory pressure. Her #'s are in the 30 percentile of predicted value.

She has started on mestinon which helped a lot the first few weeks but the effectiveness seems to be wearing off.

They have told us it is not genetic so how the heck can this happen?! I am heartbroken....debra

Debra :hug:
I'm so sorry to hear this news. I know as a mother, we would do anything in our power to make sure our children are healthy, happy and loved. I'm not aware of MG being genetically passed down from parent to child so I cannot answer that. I just wanted to let you know that I'm thinking about and praying for both you and your daughter. One good thing is that you understand what she is going through and will be able to help her which is what she needs most at this time.

Loving Hugs,
Shari

I'm so sorry, Debra. I know that it is one thing for you to face your own illness, and a whole other thing to see your daughter face it.

There is somebody on this forum who has MG--and tests positive for the antibodies--and whose sister also has it, and possibly another family member? I am quite sure it's Mike (pingpongman). If he sees this, he can correct me, but I believe he's in the same situation: the doctors tell him MG isn't known to be genetic, and yet there it is.

I do know that a predisposition to autoimmune diseases does run in families, so I suppose that means that if a parent has MG, a child's chances of getting it go up slightly.

You say that they told you they're sure you don't have a congenital (not autoimmune) myasthenic syndrome...is anyone going to revisit that question, in light of these new developments?

I wish you and your daughter strength and health. As devastating as this is, I'm glad that she's going to be spared what some young people with MG go through--not being believed, not being taken seriously. I think you had to go through a couple of full-blown crises before getting your own diagnosis, right? Your suffering is helping your daughter.

Abby

Hi Debra
I will give you a little of my history. I was dx in Aug 2010. I am currently on Mestinon 4x60mg a day plus a 180mg time release at bed time. I also take 150mg of Imuran a day. I have had 2 sets of IVIG treatments. First Ivig did nothing but got a nice bump from second treatment. I am a 70 year old male. All the neuro's I have seen all say I have generalized MG. I have double vision, droopy right eye lid and overall weakness. My first blood work came back neg but the second came back positive for binding.

Family history now. My sister (16 years younger) started having all symptoms except double vision about 5 months ago. She has seen several neuros including Duke and single fiber test at U North Carolina. One of her blood panels came back positive. But the Dr at UNC said she didn't have MG. She took his word for it and hasn't been back. (She is very stubborn) She still has symptoms. I since discovered that someone on this board was tested twice by this same Dr at UNC and twice told her she didn't have MG. Later she was dx'ed by another doctor.

My mother and 2 of her sisters had MG. All were dx'ed late in life like me. Mom and one of her sisters had the droopy necks. Neither could hold their heads up. We are pretty sure our Grandfather (Moms Dad) had it but we can't prove it. All of this said not one doctor has shown any concern about our family history.

I have one son and one daughter and just told them of the symptoms to be alert for. Neither has had the blood tests.
Mike

For some obscure reason, many neurologists (including leading MG experts) are very reluctant to consider CMS, in patients with seronegative MG.

There is a recent (relatively small) study that showed that 2/70 patients with seronegative myasthenia (one who had thymectomy and received immunsupressive treatment) had a mutation in the Rapsyn gene. And there are many other possible genetic abnormalities (in this study they only checked for a certain, relatively common mutation in Rapsyn and DOK7).

Even in seropositive patients it is possible that there is an underlying genetic abnormality. (there is one case report of two sisters with CMS and autoimmune MG).

It is possible to have genetic predisposition to an autoimmune disease, but when there is a cluster of family members it should at least raise the question of CMS. This is not an academic question because the management approach is very different.

alice

Thank you for the support and the input you guys...I really took it in but I have been definitely grieving a bit here.

She was negative in all of her tests and finally today we think we are solid. She did a pre and post mestinon pulmonary function test. Her ONLY low function is in the diaphragm. She recovers about 20% of function when we add mestinon. Our neuro thinks that he can convincingly argue that she indeed has myasthenia if she ends up needing treatment. She has a drop in function when they lie her down and repeat the testing too.

I highly recommend this testing to all the seronegatives out there who are having respiratory issues and cannot seem to get a diagnosis! I mean, she already had a clinical diagnosis by the neuro but now she has an "objective scientific marker" of the disease. It would make a huge difference if she landed in the hospital or needed insurance to pay for, let's say, IVIG.

Our neuro does not believe it's CMS because of her presentation but is keeping that in mind. He does not want to do any treatment to modulate her immune system unless her life becomes unmanageable or she is in danger. Children have a high spontaneous remission rate and we wait to treat the underlying disease. She is currently being managed on mestinon and doing well.

Debra, I'm sorry you are dealing with so much. Don't forget how resilient children are!

All I have to compare this to is my situation. I knew I had problems while growing up but ignored them or simply adjusted my physical activities. I have AChR modulating antibodies. I think it has to be a subset of MG. They should keep retesting her antibodies every few years or if she gets worse. I got worse in my late 30's, when hormones tend to change again.

I hope she continues to do okay. Does she realize that MG is all about alternating activity with rest? I sure hope you tell her how bad heat is! ;)

This isn't your fault, even though I know that's how Mom's think. I had to keep telling mine that it was NOT her fault. Sometimes life just happens this way. If you guys do have a CMS and not MG, it completely changes how you treat things.

I hope you both can deal with this and try to adjust.

:hug:
Annie