Hello.
Thank you for your query at DoctorSpring.com
I understand your concern and empathize with your situation.
It is definitely not common to posses so many genetic mutations firstly, however you're unfortunate to have already suffered during your childhood, and now to pass it on to your children.
A lot of research has gone into how genetic mutations occur, and how it can be modified so that the children are born normal. But till now no conclusive treatment has come. There are certain areas where medical science has not succeded. Cancer. HIV/AIDS. And congenital and genetic disorders.
You seem to having multifactorial inheritance and polygenic defects. But you can't blame yourself for this. Most people carry 1 or 2 defects. Unfortunately you're carrying more than 1 and it has been passed on to your children.
Can you mention about the treatment that has been given to your other children? For their AS?
A lot of research is still going on about the treatment of juvenile spondylitis. Encourage your children to participate in gym and physical activities. Are they doing any exercise? However high impact sports should be avoided for the stress factor.
Also did you get them screened for thalassemia?

I will advise you go in for a proper genetic screening and genetic counselling, where they can guide you regarding future pregnancies.
Please do not blame yourself for what happened. You're in no way responsible for this.
Do let me know if you have further queries,
I will be happy to answer if you do,
Regards.
NOTE : I have forwarded this query to one of our other specialists in the panel. I'm awaiting her reply. Once she replies, it will be added to this answer. I will try my best to help you in whatever way possible.
In House Physician,
Regards.
Kindly see the reply posted by our Gynecologist :
Hello
Relax.
I fully empathize with your sentiments.
It is the most difficult thing in the world to see your children suffer.
Let me take you through the scientific facts.
Regarding Ankylosing Spondylitis ( AS ), you never knew you were a carrier.
All carriers do not show symptoms, and there is no way of knowing which child will show what kind of presentation.
AS has multigenetic and multifactorial inheritance, there is simply no way of predicting the outlook in terms of heredity.
SO there is no fault of yours, and until birth and after, no doctor could have said that the children would have such severe forms of the disease.
It is just a tough card you draw from the deck.
Regarding thalassemia, again, you are a carrier.
The children would also only be carriers unless your husband too has the trait.
Keratoconus too has a complex pattern of inheritance, again, the outlook and severity in children cannot be predicted.
Lissencephaly is very very rare, and you have mentioned no personal or family history regarding it.
There IS a genetic component, but in the absence of any family member having it, other causes can be postulated, such as viral infections, insufficient blood flow to the baby etc.
There is again nothing you could have done about it.
Regarding yourself having so many traits , it is again rare, but happens.
Keratoconus and AS are autoimmune conditions, many patients are carriers showing such association of traits.
Thalassemia is fairly common in some ethnic populations.
To reassure you and make you feel better, if possible , you show no grave symptoms of any of the traits you carry.
There was no way of knowing them antenatally and no way , even if you knew, of predicting the exact outcome in the children.
You were unfortunate enough to have two symptomatic kids and one deceased, and you could easily have been lucky to get away with 3 normal kids, or atleast, as normal as you are, being a carrier.
HOpe that makes you feel better, knowing that you did your best.
All the best
Please feel free to discuss further.
Regards.

Hello.
It is extremely rare to carry the gene for Lissencephaly. To be a carrier and then to pass it on to children again is very unfortunate.
Since your ex husband was also a carrier, it made the chances slightly more.
But i will once again request you, not to blame yourself.
Regards.