Guest guest Posted September 17, 2010 Report Share Posted September 17, 2010 , What type of CMT do you and your son have? CMT Type 1 accounts for about 50% of the cases of CMT. Of the type 1 cases, about 70-80% are Type 1A. According to Dr. Byrd, about 1/3 of all CMT1A patients have acquired the disease through a 'de novo' mutation, meaning they did not inherit it from their parents but acquired it as a new genetic mutation. Once the person has acquired CMT1A, either through inheritance or de novo mutation, he/she can then pass it to future children, 50/50% chance. If a child doesn't inherit it, then there is 0% chance of passing it to grandchildren. Note: De novo presentation percentage and inheritance patterns vary by CMT type. Click on the link Gretchen provided and then click on your subtype to read Dr. Byrd's explanation of inheritance pattern for your type: http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance 'De novo' doesn't mean the disease skipped a generation. It means it's a new appearance of the disease in a family line, which is not uncommon. Once aquired, a de novo mutation is just as likely to be passed on to children as an inherited mutation. With regard to the genetic blood test, if you know what type of CMT your son has, the cost may not be too bad for you to be tested for that one type. The cost only reaches several thousand dollars if the type of CMT isn't known and they are testing for all the types for which there is a blood test. If the number of tests can be narrowed, the cost can be cut substantially. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted September 18, 2010 Report Share Posted September 18, 2010 Hi, , I'm actually not sure what type of CMT my son and I have. I'll have to wait til he's back from holiday to ask him. Thank you so much for the Dr. Byrd research--this is the most concise information I've yet come across addressing that aspect of CMT. Unfortunately, I have no information on the medical history of my dad's side of my family, as he died young in WWII and had no living family members. My mother's side of the family (coincidentally, with the surname Graham, like you) appears to be completely free of CMT--and there are many Graham aunts, uncles, cousins, etc., who are still alive and have no CMT whatsoever. Thank you, too, for the " inheritance " link. As soon as I find out from my son what our type of CMT is (he told me once but I didn't think it was important at the time, so I promptly forgot it), I'll click on the link. Going to another topic, I've mentioned before on this forum how my increasing peripheral neuropathy has all but put a stop to any fine-motor hand activities such as typing, fixing appliances, etc. So the other day I wanted to swap out the wall light switch in my kitchen--something in the past I would have done in five minutes while simultaneously eating a sandwich and talking on the phone. I've installed countless wall switches in my life, but when your fingers don't work right any more because they're now forever numb, you just assign such chores to other people. It's lots easier and you don't have to swear. But that day I was in no mood--I wanted my new light switch installed and I wanted it installed NOW. So for the first time in a couple of years, I took screwdriver in hand and went to work. My former five-minute project took the better part of 45 minutes, but I did it. I was so jacked up with the success of my little task that I then went outside, removed the taillight cover from my pickup truck and replaced a taillight bulb that had been burned out for the past five or six weeks. Yeah, it took half an hour, but I WON! Yours for a CMT-free future, In a message dated 9/17/2010 4:25:25 P.M. Pacific Daylight Time, agraham2k@... writes: , What type of CMT do you and your son have? CMT Type 1 accounts for about 50% of the cases of CMT. Of the type 1 cases, about 70-80% are Type 1A. According to Dr. Byrd, about 1/3 of all CMT1A patients have acquired the disease through a 'de novo' mutation, meaning they did not inherit it from their parents but acquired it as a new genetic mutation. Once the person has acquired CMT1A, either through inheritance or de novo mutation, he/she can then pass it to future children, 50/50% chance. If a child doesn't inherit it, then there is 0% chance of passing it to grandchildren. Note: De novo presentation percentage and inheritance patterns vary by CMT type. Click on the link Gretchen provided and then click on your subtype to read Dr. Byrd's explanation of inheritance pattern for your type: _http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance_ (http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance) 'De novo' doesn't mean the disease skipped a generation. It means it's a new appearance of the disease in a family line, which is not uncommon. Once aquired, a de novo mutation is just as likely to be passed on to children as an inherited mutation. With regard to the genetic blood test, if you know what type of CMT your son has, the cost may not be too bad for you to be tested for that one type. The cost only reaches several thousand dollars if the type of CMT isn't known and they are testing for all the types for which there is a blood test. If the number of tests can be narrowed, the cost can be cut substantially. [Non-text portions of this message have been removed] Quote Link to comment Share on other sites More sharing options...
Guest guest Posted September 18, 2010 Report Share Posted September 18, 2010 Hi ,  Congrats! Great success story. Wonderful perseverance.  My dad's an electrician and at 70, he's still changing light switches too, though like you it takes him a lot longer now than it used to. He loves finding little aids to help him. I can't help but wonder if a set of Built-up Handles, a Power Grasper, and/or an electric screwdriver might keep you changing light switches for many years to come.  When I was first diagnosed, learning about assistive technologies helped ease some of my fears. As I've lost function, I've incorporated many things into my home.  My hands aren't numb, but I have lost fine motor function as well as wrist/hand/thumb strength. However, I still have a mean 'monkey' grip. If something is the right width and I can get all of my fingers wrapped around it, I can grip fairly well and pull myself. So my bathrooms and staircase are equipped to allow me to play to this strength.  With my recent surgery, I have six weeks of limitations, i.e. can't bend at the waist and can't pull myself. I was very concerned at first when I learned this from the occupational therapist. How was I going to manage if I could only push, not pull? Within a few seconds, she had solutions.  I went home with new devices and new strategies and it's working out just fine. For the unexpected challenges that arose after we got home, my husband and I worked out solutions with additional devices.  If you've never met with an occupational therapist, you may want to check it out. Maybe he/she can have some helpful suggestions for you.  You may also want to surf the Internet for sites that sell assistive devices. There are lots of gadgets out there.  There is nothing like the sense of freedom that comes from maintaining or regaining independence with an assistive device. I share your joy!   From: malamutesaloon@... <malamutesaloon@...> Subject: Re: Genetics/Inheritance of CMT review Date: Saturday, September 18, 2010, 3:35 AM  Hi, , I'm actually not sure what type of CMT my son and I have. I'll have to wait til he's back from holiday to ask him. Thank you so much for the Dr. Byrd research--this is the most concise information I've yet come across addressing that aspect of CMT. Unfortunately, I have no information on the medical history of my dad's side of my family, as he died young in WWII and had no living family members. My mother's side of the family (coincidentally, with the surname Graham, like you) appears to be completely free of CMT--and there are many Graham aunts, uncles, cousins, etc., who are still alive and have no CMT whatsoever. Thank you, too, for the " inheritance " link. As soon as I find out from my son what our type of CMT is (he told me once but I didn't think it was important at the time, so I promptly forgot it), I'll click on the link. Going to another topic, I've mentioned before on this forum how my increasing peripheral neuropathy has all but put a stop to any fine-motor hand activities such as typing, fixing appliances, etc. So the other day I wanted to swap out the wall light switch in my kitchen--something in the past I would have done in five minutes while simultaneously eating a sandwich and talking on the phone. I've installed countless wall switches in my life, but when your fingers don't work right any more because they're now forever numb, you just assign such chores to other people. It's lots easier and you don't have to swear. But that day I was in no mood--I wanted my new light switch installed and I wanted it installed NOW. So for the first time in a couple of years, I took screwdriver in hand and went to work. My former five-minute project took the better part of 45 minutes, but I did it. I was so jacked up with the success of my little task that I then went outside, removed the taillight cover from my pickup truck and replaced a taillight bulb that had been burned out for the past five or six weeks. Yeah, it took half an hour, but I WON! Yours for a CMT-free future, In a message dated 9/17/2010 4:25:25 P.M. Pacific Daylight Time, agraham2k@... writes: , What type of CMT do you and your son have? CMT Type 1 accounts for about 50% of the cases of CMT. Of the type 1 cases, about 70-80% are Type 1A. According to Dr. Byrd, about 1/3 of all CMT1A patients have acquired the disease through a 'de novo' mutation, meaning they did not inherit it from their parents but acquired it as a new genetic mutation. Once the person has acquired CMT1A, either through inheritance or de novo mutation, he/she can then pass it to future children, 50/50% chance. If a child doesn't inherit it, then there is 0% chance of passing it to grandchildren. Note: De novo presentation percentage and inheritance patterns vary by CMT type. Click on the link Gretchen provided and then click on your subtype to read Dr. Byrd's explanation of inheritance pattern for your type: _http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance_ (http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance) 'De novo' doesn't mean the disease skipped a generation. It means it's a new appearance of the disease in a family line, which is not uncommon. Once aquired, a de novo mutation is just as likely to be passed on to children as an inherited mutation. With regard to the genetic blood test, if you know what type of CMT your son has, the cost may not be too bad for you to be tested for that one type. The cost only reaches several thousand dollars if the type of CMT isn't known and they are testing for all the types for which there is a blood test. If the number of tests can be narrowed, the cost can be cut substantially. 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Guest guest Posted September 18, 2010 Report Share Posted September 18, 2010 Hi , Good to hear from someone with South African connections. Pretoria is beautiful this time of year- the purple jacaranda trees will start blooming in a few weeks. Have to say I don't like reptiles,though:-) Having been newly diagnosed with CMT, I am certainly no expert. And with all the information on CMT that is out there, I can see why it can be confusing, especially if you need to find out what type of CMT you have. From my understanding (and please someone correct me if I am wrong), if you have autosomal dominant CMT it can only be directly passed on to the next generation, and you inherited it from one of your parents. If it is autosomal recessive it can be carried by someone who doesn't necessarily have the CMT and under the right conditions be passed on to someone further down the family tree. I suspect that mine is what they call " de novo mutation " . No one in my family has it, but one of my genes has mutated to start the CMT with me and it therefore could be passed down to my kids (but my kids are both adopted so that will not be the case for our family). Although, as I think of my Dad (who died a year ago at the age of 82), I am wondering if he might have had CMT. If so, the symptoms were so mild and late onset that we never suspected it to be anything other than old age (high arches, slightly curled toes, complaints about his shoes bothering his feet, balance problems, hearing loss, a weak ankle prone to sprains). However, he loved to hike and walk, and was out hiking into his late 70's, so I really don't know. As far as diagnosis goes- I had peripheral neuropathy symptoms (numbness and weakness) and also very slow NCV's on 2 occasions approximately 6 years apart. My neurologist here first tested me for diabetes, Vitamin 12 deficiency, thyroid, cholesterol- a very thorough blood test- to determine if there were any other causes for my neuropathy. When those tests came back negative for other causes, she said my neuropathy was either CIDP or CMT. The lumbar puncture was given to confirm CIDP (where the protein levels in the spinal fluid are high). My spinal fluid also tested negative- so that left her with the CMT diagnosis (on the basis of elimination of other possible causes). Of course there is no way of knowing what kind of CMT I have without having genetic testing. I think a biopsy may also further confirm the diagnosis. I suspect I may have CMT1A, but that is only a guess on my part after reading the link that Gretchen sent. I can see where CMT can be confusing since there are so many sub- types of the disease. However, since there is no treatment or cure, and since there is no way of predicting how fast or slow the disease will progress, for me, I don't think knowing my subtype really helps me in any way. Blessings, Barb Bartz Quote Link to comment Share on other sites More sharing options...
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