[tri-med] Mistakes in Diagnosis

Aussie Alex is another one who had mistakes made with his diagnosis.
Short version of the story...........
It was pretty obvious when he was born that there was "something" amiss. The 
geneticist called in to see him said that he was positive he had an autosomal 
anomaly but he then went on a sabbatical for 12 months and the chromosome 
results came back as "normal". 

For the next 15 months I was the one who was "blamed" for Alex's problems. That 
blame alternated between everything supposedly being the result of my 
imagination (now that was fun) and the problems that I had through the 
pregnancy and his supposed prematurity.

When Alex was about 6 months old his ENT suggested that he may have CHARGE 
syndrome (a genetic condition but its exact cause remains a mystery) because of 
the constellation of problems. That started us on our journey to find out.

When Alex was 14 months old a geneticist formally diagnosed him as having 
CHARGE but the geneticist died a few weeks later (from a congenital heart 
condition). We had to go back to his original geneticist who sort of disagreed 
because Alex was doing "too" well to have CHARGE. She suggested we check to see 
if Alex had something called Di George sequence - a micro deletion of the 22nd 
chromosome - because some CHARGE kids have this deletion. 

Bloods were drawn but the culture failed to grow. The geneticist wanted to 
leave it saying that it didn't really matter but by this time I was sick and 
tired of being blamed and wanted to know for sure. Not only that but one of the 
possible causes of CHARGE is exposure to pesticides an I was racked with guilt.

The third lot of bloods were drawn by my GP and I hand delivered them to the 
lab myself. On June 24th 1996, at 11.46am, a day and time I will never forget, 
not the least because it was the day before my birthday, I rang the genetic 
counsellor for the results. I only rang because I was having a teary, bad day 
and wanted some good news (how ironic)

Normally Sue was great at just answering my questions but this time she was 
evasive when I asked if the results were in. She said oh I am not sure I will 
have to check with Anne (the geneticist). I thought this was odd but all I 
could do was wait. Eventually Sue came back and said the geneticist wanted to 
speak to me - this had me intrigued.

When the geneticist got on the phone I finally got both barrels. She started 
with "we don't know how this happened but it seems that there was a mistake 
with the original test"

That one phone call contained so much, she even suggested that I consider not 
treating any further. Remember this was the child who was doing "too well" to 
have CHARGE - a condition that they would not normally consider not treating, 
and now simply because of a blood test, I mean Alex hadn't changed overnight, 
they wanted to withdraw treatment. 

They were also running scared and had already looked up past cases where a 
mistake had been made in the diagnosis of T-18. Believe it or not there are a 
few in the medical literature, including mistaking it for CHARGE. She 
apologised profusely for the error and has since admitted that had they known 
when he was younger they would not have done the emergency surgery when he was 
a few weeks old (they would have let him die from a strangulated bowel - 
painful big time) and they would not have bothered to resuscitate him from the 
apneas etc.

To this day no-one can adequately explain how the mistake was made. Given that 
Alex has such a high percentage of trisomic cells it shouldn't have been missed 
because of the mosaicism (Alex's count runs variably between 65 and 80% of 
cells effected, so even in 5 cells at least one should have shown, they in fact 
tested 20 so more than 10 should have shown the trisomy) The only really 
adequate explanation remains that it wasn't really Alex's blood that they 
looked at at birth, that is that his blood sample was mixed up with another 
child's. Other than that it had to be a lab error, but the checks in this 
particular lab are good so I think its more likely a mistake that was made in 
the hospital (they were majorly slack and incompetent even if they were a major 
maternity hospital)

Since then I have become a magnet for misdiagnosis :-) I probably hear from 
about three families a year that have had mistakes made. A couple have resulted 
in court cases, but they are hard to proceed with even when there is major 
negligence because there are no damages. (having a child with a chromosomal 
problem that later dies is not considered within the legal system to be 
damage). By and large these "mistakes" are usually just swept under the carpet. 
We need more test cases, but they cost major dollars. 

The only one that has been successful to date (settled out of court) was an 
Aussie mum who had T-13 diagnosed by amnio and who went on to terminate the 
pregnancy on the doctors advice. The resulting post mortem showed no evidence 
of any defect or of any trisomy - so in effect it appears a healthy baby was 
aborted.

If Claire has not had chromosomes checked after birth, it really should be done 
at some stage. Simply because its bad practice not to, not because I think the 
amnio was wrong. Yes genetic tests are USUALLY accurate, but amnio's are not 
"pure" genetic tests and there are possibilities for errors. Chromosome testing 
has a high accuracy rate, about 99.97% - but amnios are the highest rate of 
error in those tests (about 97%). (I hope that makes sense) In an amnio they 
are actually looking at and testing amniocytes - these are cells from the 
concentrated "soup" that the baby is growing in. That soup contains all sorts 
of cells, not just from the baby, and they are concentrated (the older the baby 
the more concentrated). The only direct test prenatally is cordocentesis (or 
PUBS) - not common because its high risk. Because they are not "just" testing 
the babies cells an amnio result should always, for good practice, be confirmed 
after birth. Actually its pretty standard to confirm. Its only a simple blood 
draw, so can be done any time they are doing bloods. It should also be totally 
covered by insurance.

I don't think anyone has done a formal study on mosaicism and amnio's but its 
generally accepted and confirmed in my own experiences that amnios showing 
mosaicism usually give a much higher percentage than what is found after birth. 
If mosaicism is detected or your doctor is convinced that she is doing "better" 
than she should, then you may want to consider a skin biospy or testing another 
body system to rule out tissue specific mosaicism. But this is a scientific 
pedantic - the bottom line is no one can tell from genetic testing how a 
mosaicer will do, its very much a wait and see game.

There are a lot of "full" T-18'ers out there that don't "fit" the doctors mould 
for what they expect of a T-18'er, and so mosaicism is or has been suspected. 
There are a lot on the list who have gone for the check and double checks. 
(anyone going to confess to Debbie :-))) but I don't know anyone in who it has 
been formally confirmed. Of course many doctors believe that ANY surviving 
T-18'er has to be mosaic, its just such a high percentage that they can't 
really see - but FISH testing has essentially said that argument is void these 
days.

So yes, even though Alex was the victim of an error in genetic testing, these 
errors are still rare. I am happy to say that they are a very accurate test - 
but if the result is not what you expect it would pay to run the test again. 
Nothing, and I mean absolutely nothing in life is 100% guaranteed. Looking back 
Alex had every possible observable sign of T-18 at birth - clenched hands, 
overlapping fingers, rosebud mouth, micronagthia, rocker bottom feet, 
hypothermia, hypoglycemia, feeding problems, the finger prints - just about 
every outwardly observable characteristic, just not the major heart defect, but 
it was missed. New geneticists will even pick it from photographs. Hindsight is 
wonderful isn't it.

Debbie, if you do get Claire's chromosomes tested again, make sure that they do 
a FISH test in addition to the g-banding to rule out any possible suggestion of 
mosaicism.

The roots of true achievement lie in the will to become the best that you can 
become.
-- Harold Taylor

Keep Looking For Rainbows!!
Karen, Mum to Alex (8 years, T-18 Mosaic)
http://members.optushome.com.au/karens
                  Building ___ooOOoo__ Rainbows
                       www.trisomyonline.org
                  Families Helping Families On-line

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