[tri-med] Re: Do you think this suspicious?

----- Original Message ----- 
From: "D McHugh"
> I want to know if you all think whether is a weird coincedence or is there 
> something very suspect here?

It's probably just a weird coincidence. Here in Australia every abnormal 
karyotype diagnosed in the first 12 months of life is notified to and 
recorded by our Department of Perinatal Statistics. I have looked at those 
results very closely ever since they were first recorded and there is no 
cluster to be seen. I even looked closely at those years when we had nuclear 
explosions, regional (was it pesticides in farming areas?), mining areas 
everything that I could I could think of. I even looked closely at the years 
during and following Vietnam, the Faulklands and there was nothing to 
indicate a cluster. (Still waiting for the stats for Iraq) Some years there 
were slightly more in different suburbs - for example I would get 3 times as 
many calls from Western Sydney areas at the moment than from say Eastern 
Sydney. Is that a cluster? Not really because the population growth and 
demographics of Western Sydney are that thats where most young couples are 
and hence where they are having more babies.

Similarly we have seen apparent clusters on the list before that have turned 
out not to be usually for similar reasons. Once someone knows that you have 
a child with a trisomy you hear of others, people who wouldn't have 
mentioned it to you before.

When Alex was born I had never heard of trisomy anything. Sure I had heard 
of Down Syndrome but never equated that with a trisomy. After he was born 
and his diagnosis was mentioned at church five women admitted that they had 
lost a child to trisomy 18 but never talked about it because even now few 
people talk about babies that have died. Its just more socially acceptable 
to talk of children who have died not babies. Thankfully that is changing 
but its a slow change.

The generally accepted science is that trisomy is a random occurence and not 
related to environment. Remember that most (but not all) additional 
chromosomes are maternal (meaning that its the mother that gives two copies 
of a chromosome and the father usually only one). If the accepted theory, 
that the egg was in fact trisomic before conception then any environmental 
factor would be related to your mother because a womens eggs are formed in 
utero not after birth. In fact some very recent research is indicating that 
trisomy 21 results from ovaries that are mosaic trisomy 21.

I am still trying to get information about the research and to verify it but 
the abbreviated version of the research is that some scientists did studies 
on unborn fetuses (that did not have any chromosomal abnormality) and found 
that they all had mosaic t-21 ovaries. They feel that the development of the 
T-21 is caused by some sort of differential selection. For example the non 
trisomic eggs develop first and the trisomic eggs develop when they start to 
run out, and that would account for the increased incidence based on age. 
Exactly what causes that differential selection we don't know. (why does any 
egg mature when it does and not another one?) It was only a very small 
study - 8 fetuses - but it certainly is interesting and sounds very feasible 
according to what we do know - and bear in mind that we don't know much.

Now these scientists only tested for T-21 and its very possible that there 
were trisomic eggs there for other chromosomes. It would be interesting to 
know but then again I am not sure that I am completely comfortable with 
doing research like this on unborn babies, stillborn children, miscarriages 
or terminations. (for the record I am not sure where I sit on this issue, 
none of it makes me feel comfortable)

So by all means ask for an answer but I think you will find that their 
answer will be that three babies don't make a cluster and its not all that 
unusual. Given that t-13 occurs approximately once in every 9,500 births 
(not pregnancies) and if you average it out that every women will have 
approximately 5 pregnancies in her life (2-3 live born children and 2 
miscarriages) that equates to approximately 1 in every 2000 women will have 
some experience with t-13. And thats not taking into account the fact that 
T-13 can be associated with Robertsonian translocation and may therefore be 
hereditary and the same parents may have more than one child with T-13. So 
if in your geographical area there are 2000 women pregnant 3 babies in 3 
years wouldn't be unusual. Also remember that although you are more likely 
to have a baby with a chromosomal anomaly as you get older the majority of 
babies with chromosomal anomalies are in fact born to younger mothers simply 
because they have more babies than older mothers.

Life consists not in holding good cards but in playing those you hold well.
                                            -- Josh Billings

Keep Looking For Rainbows!!
   _--_|\
 /Karen \
 \ _.--._ /
          v Karen, Mum to Alex (13 years, 14 in 15 minutes time T-18 Mosaic)
http://members.optushome.com.au/karens



                  Building ___ooOOoo__ Rainbows
                       www.trisomyonline.org
                  Families Helping Families On-line

Other related posts: