Genetics of diabetes

My son was diagnosed with t1dm when he was four year old. Can anyone help me to know what is the probability of same thing happening in case I plan another child. Is there anyone who had kid already with t1dm and planned for one more.

Well, the answer is complicated. First, you must understand, nothing is absolutely determined by genetics. Even eye color, you could have two blue eyed parents and still end up with brown eyes. It is thought that T1 is a complex interplay of genetics and environment. Generally, having an immediate relative with T1 means that you have a 10-20 times greater chance of having T1. If one child has t1, their siblings have a 1 in 10 chance of developing T1 by the age of 50. You can compare this against the average american having a 1 in 100 risk of developing T1 by the age of 70.

Below is a chart showing some of the risks (note that there is some variation in the chances quoted, but they are similar).

There is no single gene connected with T1, although there is a gene called HLA-DR that is clearly more associated. I think many parents fear having another child that will get T1, but there is clearly another side to these issues. You don't know whether your child will go on to be a nobel prize winner or a great athlete. If you just minimize the downside, you lose all the upside. And I think it is really hard to find someone who will tell you they just wish they hadn't been born. Life can really be a joy both for your child and for you as a parent, even if your child has diabetes.


BSC's explanation is a good one. What our family has been told is that if a father has T1, his children have a greater chance of getting the disease than if the mother has T1. If a child has T1, his/her siblings have about a 10% chance of acquiring the condition as well. I have T1 and so did my father; my sister does not have T1, but she's been told she has as much as a 25% chance of developing the condition at some point in her life.

But you have to remember that genetics is a total game of chance. Every single time you have a child, you're basically rolling the dice for all sorts of problems.

In our family, it's autoimmune disease that is being passed on, not just T1. No one in our family had T1 until our daughter in 1973 suddenly had it. Then I didn't get T1 til 2001. Rheumatoid arthritis has been the autoimmune disease, however, that has been in the family for a few generations. Maybe you can get an idea by looking back at the generations before or get a medical genealogy in place to give you more advice.
After all the problems we all had through those years of inability to control spikes, no meters, diabetic team members in a university setting who taught my teenager that it was ok to ride high (eat what you want), resultant kidney problems, amputation, retinopathy with blindness, transplant, etc., I have had my fill. I don't believe I could have handled another child appropriately, even one who was free from diabetes. And it doesn't stop when they're out of the house and "on their own". This one got on her own but has always had medical problems of one kind or another.
So I look at having children as knowing that sometimes it's better not to. I would never in my life have planned for another child who might go through similar circumstances. There was not ever a day when diabetes didn't have to be taken care of and planned for.
I'm glad I didn't have more children, and the rest of the family is very glad I didn't, too. We have many medical professionals in our family. This gives you an idea of what one professional family did when T1 turned up: we stopped having babies! We found the questions overwhelmingly poorly answered by genetic counselors/professionals.
Get all the information you can. Go to genetic counselors; get the parents tested to see what you're passing on. And you have all my best wishes as you make your decisions. These are tough ones.

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I truly did not mean to turn off people to your discussion! I hope they will come on with their opinions and information!
I remember being so overwhelmed and could not have had a second one with diabetes or without diabetes afterwards! Nor could my partner-physician in the family! I hope others will come on and give more comments!

Why? Of course, you were overwhelmed. Anyone would be. And, as said above, your T1 child could be (almost) anything in the world. An artist, doctor, scientist, Pulitzer or Nobel prize winner. We could really use a POTUS as an advocate in the White House. Would you give that up, just because of Diabetes? Not create a life because of that possibility? Would you have chosen not to have your son, if you knew before that he would be D?

You are not turning folks off. I see a lot of the info above, but when I was diagnosed, I was told directly that my children would not have T1, but their children would. Such BS. I am the only T1 in the 5 generations I can delineate. There was a poll when I was diagnosed in 1961 to determine the person whose gentics "caused" my T1. No one knew anyone, but it was hard to diagnose, as it was refered to as consumption.

The discussion of genetic heredity is widely discussed. D is a "thing" in life and lots of people have "things."

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When my daughter got it, it was said to be mumps that had been within 2 years, thus "caused" it (no one had it in the prior 5 generations and wwe had a good medical genealogy & death certificates for the 1850s on up). Then when I got it, it was said to be "stress". Hogwash. It was autoimmune, and for that we had 3 generations.
We were in all the genetic studies of the time. (They never counted back to MY generation!) Such a changing field.

I met genetic counsellor, according to her the gene variant which has been understood to be associated with t1dm is also present in people who dont have type 1 diabetes. She said the role of environmental trigger is more probably. and same environmental factors occuring again is less possible and If I am interested I can plan for another child. But I was keen on knowing whether anyone has taken such decision.

I always thought consumption was the common name for Tuberculosis.

Anu, there are a number of folks here on TuD and blogging who have had another (or 2 more) children after one was dx with T1. It's a crapshoot, and a very personal decision. Sounds as if you've done lots of research and taken the right steps towards making an informed decision.

Of course there's always the option of adoption. My 3 are adopted, so I'm a bit prejudiced towards it ;)

Of course this is a personal decision. But the mathematician in us all should really look at the odds. Your child will probably not become the next world leader, sports star or Nobel prize winner. You will have a child you will likely love and cherish. If they have diabetes their life will suck quite a bit of the time. They will face great challenges. Odds are they will die sooner than much of the rest of the populace. Medicine and technology will advance, but cost more every year. There will likely NOT be a cure.

Think it over and roll the dice.

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My diagnosis was similar to your daughters. I had strep throat a few months to a year before my diagnosis and they told me it was likely that it triggered an auto-immune response leading to the destruction of my islet cells.
The only other person in my family who had Type 1 was my great-grandmother.

Hi. I want some happiness in my home. whole day and night is spent on mananging my son's diabetes. Only thinking that a small baby would bring a happy moment and joy for us and also sometime distraction from worrying about my son's health

Anu, I'm not a type 1 but I do know something about genetic diseases. My oldest son, notice I said oldest son, has a genetic eye disease which is causing him to lose his sight. At the time he was born we did not know that his grandfather's eye disease was genetic. Nor did we know at the time my youngest son was conceived. Had we known we would not have a second child. But the youngest was lucky, even though he had a 50-50 chance of inheriting this disease he did not.

Now to my point. Had we known before my youngest son was conceived I would not have my youngest son. Had we know before our first son was conceived I would have no children at all. If I could go back 30 something years I would still make the same decisions even if I had known. I cannot even imagine what it would have been like to not have had my sons to raise to manhood. I have 2 son that I will do anything for. Just think I might have made a terrible mistake 30 something years ago.

Gary S.

Is this true?

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The chart is pretty straight-forward, butI think eye pigmentation can be a little more complex at times - I have brown eyes, my wife as blue - 3 of my four kids have blue eyes and one brown – but, there is nearly no similarity in the shade of blue between my three blue-eyes kids. I’m thinking, perhaps, there are occasional (if rare?) recessive browns…

Here is a detailed discussion of how this happens.

Wow. Thanks for the clarification. Very helpful. :slight_smile:

I was the first diabetic in my family, my elder brother was the second. One thing I would say is that I would much rather be alive and be diabetic. Diabetes does not influence who i am and while I would rather not have the condition, I do not believe that the risk of being diabetic is a reason not to have children. If diabetes is your only worry regarding having more children, I would say have another. However it is personal preference and if I were you, I would do what ever you feel comfortable doing.