A question for MILLARKIE please...

[HerbertSnodgrass]

Millarkie, you once helped me very kindly and I need your knowledge once again.

A lady on this thread had a CVS on thursday, and the next day she was informed of a 46XY result.

I had a CVS a few weeks ago and the lab once again put me through HELL waiting for results, causing rows and faffing about. They swear blind that there was no way they could have told me 46XY the next day, or even within a week. I am trying to challenge them as the distress of waiting was dreadful. They did FISH (eventually, after I spoke to them at length) and PCR, but they are telling me that they could only glean bits of information about certain chromosomes and not the full karyotype.

I think they are lying to me. How is it possible that the lady on the thread I linked to could have her results so quickly?

ALL I wanted to know from the lab was

1. How many chromosomes does the baby have, 46 or 47.
2. Are any of them rearranged.

I wanted question 1 answered with the utmost urgency. I was happy to wait for the final results to question 2.

Even though all is well with my baby, thank God, this horrible experience is still eating away at me because I went into this prepared, or so I thought, I had even prepeared a briefing note for the lab on the types of tests and probes that were specific to my chromososme rearrangement.

I actually want to formally complain by saying "THIS test was what you should have done, and the preliminary chromosome count results would have been available within a day, and you bloody well know it."

Please can you help me to understand what test I should have explicitly asked them to do?

Thanks

Herbert, as far as I know, the full karyoptype is only available after cell culture, i.e. growing your cells on a dish. This takes a few days and hence you only get the results after 2 weeks. The quick results (FISH or PCR) are done on small amounts of material and therefore can give results quickly (2 days), however they only look at specific chromosomes: 21 and other 2 or 3 where typically problems are detected.

So, I think the lab was not lying to you. They couldn't possible confirm after 2 days only the full number of chromosomes.

Hope this helps and I'm glad all is well with your baby!

Herbert - I already answered on the other thread but using a different posting name.

The test that would need to be carried out to get a chromosome count and a look for very large rearrangements (i.e. robertsonian translocations) is called a 'direct' prep and most labs in the UK are no longer funded for this test. This means that they cannot carry it out even if they have the know-how because the 'commissioners' have decided that in that region this service is not provided by the NHS. THis has been the case for some years and the test is no longer taught as part of the training for genetic scientists so in some regions they may not have any staff who can carry out the test.
There are drawbacks with the direct prep test in that it tests cells from the placenta which are not as closely related to the baby as the cells which are cultured and karyotyped so it can give false negatives and false positives and always needs to be checked by a second test. It also needs a lot of skill and is expensive (labour intensive and takes a long time for 1 patient) compared to FISH and QF-PCR which are a lot cheaper, and test a mixture of cells.