Hi. I'm autistic also. Does your son have an unusual appearance,
birth defects, etc as well as autism? If so, he may well have some
kind of syndrome, possibly chromosomal. But autism is very common
and most autistic kids don't have any syndrome causing it, the cause
is not known.
With regards to having multiple kids with trisomy 9, it depends on
the type. Mosaic trisomy 9, where the child has an entire extra
chromosome 9 in some of their cells, is highly unlikely to happen
again. But if a kid has partial trisomy 9, it could be that the
extra piece of chromosome 9 is attached to another chromosome, in
which case the parent may have a balanced rearrangement involving
chromosome 9 and the child has an unbalanced form. Which means that
they could have another kid with partial trisomy 9 or the opposite,
partial monosomy 9. And their normal children could inherit the
rearrangement in the balanced form, and therefore have partial
trisomy or monosomy 9 children.
Secondly, it could be that the parent has very low-level mosaicism,
which would mean that some of their cells are abnormal, but not
enough to have a noticeable effect. But if that includes cells in
the ovaries or testicles, they could have multiple kids with a
chromosome abnormality. Their unaffected children would not be any
more likely to have a child with a chromosome abnormality than
anyone else. Also, it's unlikely that kids with mosaic trisomy 9
would result - they'd either have full or partial trisomy 9,
nonmosaic (all the child's cells are affected). Full nonmosaic
trisomy 9 is fatal, but nonmosaic partial trisomy isn't.
Ettina
--- In trisomy_9q@yahoogroups.com, "shanley_n_teresa"
<shanley_n_teresa@y...> wrote:
>
> My baby brother was born with Trisomy 9 mosaicism back in 1981, he
> died at the age of two.  When I became pregnant with my daughter I
> was terrified that she might too have it, so I went to a genetic
> doctor who said that no, my probability of having a child with
> trisomy 9 was almost impossible as it is not hereditary.  I did
> notice that at least one of you have two children with trisomy 9. 
> How can that be if it's not a hereditary issue. 
>
> I have a 3 year old son who has been diagnosed with autism.  Now
I'm
> really curious to know if he may, in fact, have a trisomy of some
> sort.
>
> Forgive me for being so ignorant...I was very young and the
disease
> was practically unheard of at the time I dealt with it.
>
> Teresa
>