Calling Tamum and all other mumsnet geneticists please - looks like we finally have a dx and I need some help please.

[merlot]

Hi everyone,

Well it looks like we finally have a dx for ds2.
I feel relieved that the search' is over but also saddened that we now know there is something physical causing ds2's special needs. Another complication is that I am troubled by the quality of antenatal counselling we received and would be very grateful for your views on this. I need to understand things more clearly before I can reach any degree of closure' iykwim.

Some of you will remember that my DH carries an inversion of chromsome 15 and as a result when I was pregnant with ds2 in 2002 I had a CVS test which was ordered by my GP on the strength of a letter written to her in 2000 from a geneticist who had advised that because of dh's inversion we should have a CVS test to identify any genetic abnormalities.

The CVS test was carried out at Kings College Hospital by Prof Nikolaides and I was rung up by a nurse 2 weeks later to be told that all was well and that my CVS had tested negative to genetic abnormalities. Are you sure? I asked and she replied yes. However, she said that there was a statement on the results which said Under Standard Resolution testing Chromsome 15 looked normal, but we do not have details of the father's rearrangement'. I asked her what this meant and she said that she didnt know but would send me a copy of the report. I, in turn, asked my GP what the statement meant and she replied that she didnt know, but that fine meant fine' and that I shouldnt worry about it.

Ds2 was born and it was clear to me fairly soon after birth (6 weeks) that things were not right and he didnt seem as responsive as his elder brother had. It also became clear that ds2 has only one kidney, something that had been dx antenatally as hydronephrosis.

We then began a round of investigations and consultations with a developmental paediatrician who ordered some genetic tests which turned out to be fine again.

Sorry for all this rambling...but I am nearly there now...

Anyhow we have just discovered that Matthew does in fact have a genetic anomaly, but that it would never have been detected by standard resolution testing: He has a 15q sub-telomeric duplication, which is entirely consistent with the fact that ds2 is so tall (because a duplication leads to an extra copy of a gene called IGF1R which has growth factor and can result in overgrowth)

Apparantly 15q duplications are uncommon and therefore we still do not know much more about what this means for ds2.

My unanswered questions are these:-

1. What do you think of the quality of the geneticists advice in 2000? He made it sound to us (and obviously the GP) that a CVS would identify any genetic abnormalities - which was clearly not the case. Was this sound advice in 2000 given the info they had then. Was it known that CVS might not detect minor alterations in genetic makeup? Was there any other sort of tests available to us antenatally that would have examined the telomeres?

2. What do you think about the GP ordering the CVS without reconsulting the geneticist. It strikes me that with the leaps and bounds that are being made in research in this area it was rather foolish (??) to order genetic tests without reconsulting the geneticist again to make sure that this advice was still relevant. I did, in fact, ask the GP whether we should see the geneticist again when I fell pregnant in 2002 and she was quite clear that there was no need. `It says here that a CVS is what needs to be done...' etc..

3. Whose job was it to pick up on the statement in the genetic report copied to my GP and myself from Kings College re-the we do not have details of the father's rearrangement?

4. If Kings had been given details of the father's rearrangement in Feb 2002 what tests would they have done?

5. Finally, where the heck do I go from here.... I love my ds2 completely and utterly and know that my sons special needs are what make him, him. It would not be possible for my son to be here without his special needs - I accept that. However, I cannot help but think what life might have been like for the rest of us...had we been given all possible choices and more significantly if the advice had been different in 2000, I could have chosen not to conceive at all. I also am keen that lessons should be learned from this and that the best possible advice should be given to others who might find themselves in our position.

If you have got to the bottom of this post - thankyou. I really would appreciate your help and views

Yes Tamum - 18mths ago when they started testing ds2 genetically, I got copies of all the paperwork held at the Dr's surgery regarding this (was scared that it might be altered at a later date!) I think the time has come to find out what information Dr Patten actually had in front of him when he counselled us.

Fio - in the vast majority of cases if a child inherits an 'unusual' chromosome from a parent and it looks identical by standard cytogenetic methods the child is clinically normal.
There is a tiny chance of a disruption of a gene at the site of the rearrangement which may cause no problems in a parent (as we have 2 copies of each chromosome so they may have a working copy on their other chromosome)..but in a child there may be a clinical effect (as they inherit their other chromosome from the other parent, so the other parent may carry a non-working copy of the gen on one chromosome and give this to the child).. the child ends up with 2 non-working copies of the gene (e.g. 1 due to the chr abnormality and the other due to a DNA mutation)
The chance is reallly really tiny but theoretically there. There may be a different genetic component to your friend's family's situation - at the DNA level- a chromosome test gives a very broad picture of the genome.
The technology used in chromosome testing is changing incredibly rapidly - in my area we will re-test patients if their last test was more than 5 years ago so we can apply new technology. There is no harm in asking for a review.
BTW - not sure what 'bent' chromosome is - they are like little worms - always bendy!

Merlot - I would hope your geneticist would have got hold of the full report before seeing you - it is usual practice.. a lot of patients get referred for genetic counselling after being tested via other specialties. I really believe that your geneticist recommended all that was possible at the time.

Thanks everyone for your advice and views on here - it has been much appreciated and as much as anything its been good for me to `get things off my chest'.

Also, I cannot help but think, if there has been a degree of negligence - it has resulted in me having a lovely little boy - whose needs may be challenging, but who brings sunshine as well as rain iykwim. There are others out there where medical negligence has meant actual loss of a family member and I cannot begin to contemplate how they must feel

Merlot x