Disability that runs in a family?!

[AmyLeen]

My partners brother has a child who is severally disable, he has combination of different abnormalities, epilepsy, brain damage and so on. The boy is 4 years old now, they have two year old as well, he turned 2 in May, so just over two now and it is quite obvious he is not developing as he should?He can?t walk, talk, chew, he cant even seat without support, if you put him on the floor he just aimlessly rolls all over the place, he doesn?t play with toys, he can?t swallow any solid food, if it?s just a tiny lump he gags. Hence, you can really tell something is wrong he has quite a large head too. We confronted his brother and he told us that the boy is just lazy and doctor is not worried that he is SLIGHTLY behind!!!! They said that all children develop differently and he will catch up! Me and my partner?s main concern is that we are planning to have a baby, but sick worried now that something runs in his family, surely, there is something if his brother has two children who are obviously disable. I had a look on the internet and it says that the most common causes of GDD are problems with the child's genes or chromosomes. I was wondering if anyone ever came across such a problem. Or maybe I am just being paranoid and the second one is really ?just lazy??

Firstly, unless it's the same abnormality then it isn't genetic, there isn't a gene for "generally being disabled". If it is genetic then your dp may still not have it, he'll only share some of his genes with his db.

In very basic genetics, then as your dp and his db don't have it, then it must be recessive-ie you must also have the same abnormal gene for your dc to develop it. That's very basic, so someone with more knowledge may well correct that.

What you describe is very behind, but it may be that they know more than you almost certainly, and it may be that something has happened which they know about, which they don't want to discuss.
Now I suspect that the way you approached this may have made dp's db very defensive, approaching it from "we're worried about our future children" when he's worried about his current children will have come across as insensitive to say the least.

And lastly, you do get families who have more than one disabled child which aren't connected. I know of one who have three dc, all of whom have some level of disability, none connected. One is birth injury (cerebal palsy), one is a congenital limb amputation, and the other is genetic (cystic vibrosis).

What DeWe said about genetics.

To know if there is a potential risk to your children you would need to know:

a) what it is that is causing the delays for both these boys and if it is the same thing.

(If the elder boy's delay has been described as "brain damage" that suggests a birth injury rather than something genetic, so wouldn't be any more hereditary than having been in a car crash- but the description could be wrong of course).

b) if it is genetic, then how this particular condition is inherited.

(For instance we have a genetic connective tissue disorder in our family which causes chronic pain and mobility problems but no learning difficulties. This is a dominant gene, which means that if a baby inherits the gene at all, it will inherit the disorder. As far as we can tell, my brothers have not inherited the gene, so their children/grandchildren etc are probably safe. I have inherited the gene, but that is not the end of it:

every person carries a double set of genetic material, so I wouldn't necessarily pass on this gene to any child of mine, there is a 50/50 chance

not everybody who inherits the condition is equally affected- I've led a perfectly normal life, my dd hasn't.)

Thank you for your answers. And DeWee, I didn?t put it the right way, we haven?t approached them with our plans and worries about our future children, we just raised concerns regarding second child not developing the way he should (please note very delicately). They simply said nothing is wrong and he is just having developmental delays, but we can surely see that something is wrong! Plus, they were told by health visitor with their first child that he just had nervous twitch (!), while he was having epilepsy fits and that he is being late with his milestones, but now he has a bouquet of disabilities that wasn?t spotted on time, and it is so upsetting! Now, their second child is a spitting image of the first one apart from epilepsy, its just all the same looking( I mean the symptoms and all this delay), the doctor said that he has indeed has global development delay same as the first boy, but surely it can not be just a coincidental? I just can?t see how it?s possible that doctors are not trying to find out what causing these delays in development and what the underlying causes for all that?! I?m in complete shock from all this! It?s just these boys mum is from very disadvantaged background and my brother in law is very young and so immature, I don?t think they understand how serious this all is, they just keep having children, to add that she is pregnant again

Well, since your partner's brother doesn't have any of these problems himself, if it is genetic then it would have to be recessive, like DeWee says.

If it is a straightforward sort of genetic problem then that means the child must have got two "dodgy" copies of that gene, one from each parent.

Your partner will have about 50% of his DNA in common with his brother, so it's only 50/50 he'd have a dodgy copy.

And there's no reason to think that you just have the bad luck to also have a faulty copy of this same gene.

What it all boils down to is that, even if it is something genetic, you'd have incredible bad luck for any of your children to be affected by the same thing.

If you were really still very worried about it, then your GP would be able to refer you to specialists who would be able to talk it through and give you a better % risk for this, but I don't think it should stop you from geting on and having children.

AmyLeen, global developmental delay is a diagnosis. I'm not surprised that they reacted badly to your comments, you've come across as very judgemental on this thread. If you're genuinely worried, educate yourself on this topic and get genetic counselling.