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#16229 - 07/25/07 04:58 AM
Re: Gentics of CIE
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Member
Registered: 01/29/06
Posts: 205
Loc: Brisbane, Australia
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G'day Lisa Marie, The best way to answer your question is to direct you to the Rare Deseases in Sweden website, which has a fabulous section on Lamellar Ichthyosis. (relatively recently Lamellar Ichthyosis and Congenial Ichthyosiform Erythroderma (CIE) have been grouped into a large group known as Autosomal Recessive Congenital Ichthyosis or ARCI for short) I will endevour to answer your questions here, but the website address is: http://www.sos.se/smkh/2002-110-7/2002-110-7.htm (scroll down to the "Heredity" section) It is generally accepted that when your parents had each child, there were 4 possible outcomes. A healthy non carrier, 2 healthy carriers and an affected child. Essentially a 25% chance of having someone with Ichthyosis. As for your children, if your husband is a non-carrier then your children will in theory be healthy carriers of one of your affected genes. If on the other hand your husband is a healthy carrier, then you have a 50% chance of having an affected child and 50% chance of having a healthy carrier. It all depends on which genes each of you pass on to your child. Its a bit of a lottery, like most things in life. Although I have painted a fairly black and white picture, I should point out that there is plenty of conflicting research out there, despite the majority of it coming from respected research organisations. All the best with your first child! May they be born happy and healthy! Jeff
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#16232 - 07/10/08 01:48 AM
Re: Gentics of CIE
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Member
Registered: 01/16/04
Posts: 1449
Loc: Richmond, VA, USA
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Deb,
Mutations happen at a fairly constant rate in the body. Genes make proteins. You need 3 bits of DNA to make an amino acid, and proteins are made of long strings of amino acids folded into various shapes. There are 64 possible combinations of the 4 DNA bits, and only 20 amino acids, so many AAs are made by 3, 4 or even 5 options. Most mutations happen so that the AA doesn't end up changing. For example, if the code for adenine is usually AAA, a mutation to AAT or AAG still results in adenine, so there's no protein to break down.
Spontaneous mutations that cause problems happen at a pretty slow rate. It's around 1 in 40,000 or so, and even then, most of those are fatal and result in very early miscarriage. Because they are so rare, most spontaneous mutations that cause a survivable genetic disorder are caused by a dominant mutation - 1 "bad" copy overrides the nonmutant "good" copy. (Terms used loosely, as sometimes the mutant is actually better than the original, but that's evolution.) Ultimately, the rate of having a survivable mutation comes out to around 1 in 300,000, which is about how common EHK is.
In your case, your son has CIE. It is a known recessive problem - you have to have 2 "bad" copies before the problem shows up. Because the carrier rate (people with one good and one bad copy) is so low (1 in 250), it can take generations for someone to marry and have children with another carrier. Even then, only 25% of the offspring would be affected, and if the child was born before 1940, child mortality was really high so a child affected by a birth defect was very likely not to survive, even though the carrier siblings did.
With all of this, yes, there are 3 options:
1. You and your spouse both spontaneously mutated the same gene AND passed it on to your son. Odds: 1 in 300,000 x 1 in 300,000 x 1 in 4 affected. Chance is 1 in 360 billion. There are only 6 billion people on the planet.
2. One of you had a chance mutation while the other was a carrier AND you both passed it on. Odds: 1 in 300,000 x 1 in 250 x 1 in 4. Total chance: 1 in 3 million. This could possibly happen, as there are about 4 million babies born in the US in a year.
3. Both of you are carriers and you both passed it on. Odds: 1 in 250 x 1 in 250 x 1 in 4. Total chance: 1 in 250,000. This accounts for nearly every one of the 30 or so kids born with CIE/LI in a year.
Now that you have an affected child, the chance that it will happen again depends on whether you are in group 2 or 3. In group 2, your chances are about the same and you should start playing the lotto!
If you and your husband are carriers, your odds for future affected children are 1 in 4, and 2/3 of the unaffected kids will be carriers.
To answer your other question, no, you didn't do anything to cause this problem. Even if somehow you fell into the first two groups, it's pure chance that any particular mutation would happen. It could have been a heart defect, Downs, cri-du-chat, etc. There's no practical reason to test 4 million babies for a disorder that affects 20 of them, so there's really nothing you could have done. This isn't something that gets picked up on ultrasound or via amnio unless you are actively testing for it. Fairly often, families with CIE/LI have 2 or 3 kids, then it suddenly shows up in the youngest, and it's just as much of a surprise.
Now that you know you have it, you can test future pregnancies in advance if you feel it is important. If you know your gene, which is likely with CIE - 90% are known causes - you can undergo IVF/PGD if you want to make absolutely sure it doesn't show up again. Another option is to do an amnio once you're pregnant if you think terminating is an option (many of us don't, but a few have made that choice), or if you feel that you want the warning about that child's needs at delivery. Or you can adopt and not risk the odds again. Or you can go on with your life and accept whatever child comes into your life, affected or not. It's a very personal decision, and all of us here face it sooner or later.
Jennifer
------------------ Reticular Ichthyosiform Erythroderma with white spots. Husband, Nathan - 5, Elliot - 2, all affected. I also have an unaffected daughter and am pregnant, due Oct 12, 2008
_________________________
Jennifer Ichthyosis-en-Confetti Type 2 Husband, Nathan - 10, Elliot - 7, Oliver - 4, all affected. I also have an unaffected daughter, age 8.
email: jennifer at confettiskin dot com facebook - find me on "ichthyosis mommy spot" or "friends of ichthyosis"
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#22642 - 09/14/08 01:06 PM
Re: Gentics of CIE
[Re: libby]
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Member
Registered: 02/25/05
Posts: 356
Loc: USA
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#22786 - 10/07/08 06:46 PM
Re: Gentics of CIE
[Re: libby]
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Member
Registered: 08/08/05
Posts: 401
Loc: Detroit, MI, USA
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Hi. In response to the question of skin changes with ich. I am 42 with possible lamellar or cie. My skin was at pretty bad as a baby and a young child. My mom moisturized my skin, had me soak in oil baths, combed my scalp, used the acid based creams and most importantly the over the counter creams to comfort my skin and make it look as good as it could. About age 12 my skin started looking much better and it did throughout my teens and most of my twenties with me still taking a lot of care of it. Early thirties hit me kind of hard with my skin drying out more and now at 42 it dries out even quicker even though I still take as best care of it as I can. I do give some credit for how my skin is doing now to the colder and dryer climate here in Michigan. But, I also believe that as I age that also plays a big part. As far as friends, I had many great friends around me as a child and teen and dating had its awkward moments because I would try to hide my hands and feet and sometimes I would not want to be seen in shorts depending on my good or bad days with my skin. I married really young, at 18 and I had four children starting when I was 27 and the last one at 35. Mostly I consider my life normal with a few inconveniences from my skin cracking, especially on my feet making it hard to walk and the extreme cold or extreme hot being very difficult to deal with.
I use St. Ives Mineral Therapy (18 oz) mixed with 12 oz of glycerine all over my body two or three times a day and little bits at other times through the day. I bathe in non-iodized salt(alot of it) and bath oil, sometimes use St Ives apricot scrub or a heavy duty scrubbing pad with Olay shea butter wash conditioners for dry and damaged hair and I lay in the water rubbing loose any dry skin on the scalp that I can, and immediately moisturize after my bath twice from head to toe, and comb out the dry flakes as best as I can. I also use petroleum jelly on my skin before going out in the cold and my lotions and petroleum jelly on my feet and hands before bed then I put on cotton gloves and socks to try to hold the moisture. The weather really messes up my skin when it turns cool or cold out. Could that be what is happening to your daughter? Remind her to avoid going out in the cold for about the first hour after she moisturizes and to coat her skin with petroleum jelly or something along the same lines during the winter to act as a barrier. I hope this helps some. Good luck to you and your daughter.
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#23074 - 10/30/08 06:15 PM
Re: Gentics of CIE
[Re: wva]
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Member
Registered: 03/09/05
Posts: 271
Loc: Grand Junction, CO, USA
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Happy 13th b-day to your daughter!
My skin was pretty bad as a kid, and didn't really improve until I hit puberty. Unfortunately, I was a "late bloomer" and didn't start menstruating until I was 16. Jr High was awful for me. High school wasn't so bad, once I got involved in things I liked and I had a great support system of friends!
My skin REALLY improved when I turned 18, and my, um "chest development" hastened at about the same time--leading me to believe it was probably my hormones that helped improve my skin. My skin also improved during both pregnancies.
I haven't seen any "downturn" like WVA yet, but I'm only 29. I use VaniCream during the summer, with Nivea Cream on my face. In the winter, I use Velvachol. It's a little bit stronger (and more expensive). Both of them are great moisturizers, and are water-soluble so I can wash them out of my clothes and bedding easily enough. I use Vaseline on my feet, though. They've always seemed to need heavier moisturizing.
_________________________
If the grass looks greener on the other side, maybe it's time to start watering your lawn!
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#27892 - 08/18/11 03:25 AM
Re: Gentics of CIE
[Re: immystique]
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Anonymous
Unregistered
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Hey, Libby, I'm not sure if you're still interested in a response to your question, as it's from a few years ago, now, but I'm replying anyway  I have CIE, and am in my mid-twenties. I found it bothersome but not so bad as a teenager, though I have always been a very confident person. I have not dated much--but that's not because I haven't been asked!--those who I've dated haven't been so bothered by it, even though it's visible. My mom always told me that having something physically different helps "weed out" the jerks. Good people to date won't care what you look like! As to improvement--well, I've not really had any improvement, in fact I think the appearance is *a little* worse, but this is balanced out by knowing how to care for it better/more effectively. I used to use Vaseline, but now I use Eucerin, and I have found the dryness and flakiness has greatly reduced. Really, I'm so amazed by this, b/c it's a very recent discovery for me. If you're daughter ever wants someone to talk to, I'd be more than happy to hear from you. I know that as a kid, I would have loved to talk to someone who led a "normal" life who is only just beyond the teen years, as I am now.
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