My DD has a MRI scan under sedation. She was about 15 months at the time and would not stay still so had to be aneasthetised. The MRI scan diagnosed possible synosostis but on further examination (referall to GOSH), this was ruled out. We then went the genetics route and finally received a diagnosis of Sotos Syndrome (global developmental delay and overgrowth).
Before the genetic diagnosis, the geneticist asked lots of questions about our families, histories, other children in the family (not just our children, but nieces, nephews, etc.). Took some blood from me and ex-h but luckily they still had some of my DD's blood from previous testing.
The geneticist we saw thought she knew what it was and called in two other geneticists who happened to be working the same day who were specialists in Sotos. Just by looking at my DD and hearing her history, they visually diagnosed her. This was later confirmed by the blood testing.
The FISH test is a test carried out on certain chromosones that can pick up certain disorders - in Sotos Syndrome this is chromosone NSD1.
Neither me or my ex-h are carriers, our DD was just a one-off mutation that occured. She has a 50% chance of passing on the syndrome as she has tested positive but this will depend on the child's father. If he does not have sotos syndrome, the possibility is 50% but the doctors have said that my DD can have genetic counselling at the time, if she so desires, regarding passing this on. Even if her child's father does have Sotos syndrome, if the child receives one part of the chromosone from my DD's good side and receives the other part of the chromosone from the child's father's good side, then the child will not have Sotos. If the child picks up one bad side then that child will have Sotos syndrome. Obviously if the child's father does have Sotos syndrome, the possibility of passing on the defective gene is that much higher.
(Seems strange talking about my DD's possible children, she may never be in a situation to have children, she may not want children, she may not be independent enough to have children - just have to wait and see - but I like to think she will grow up to have a 'normal' life (whatever 'normal' is).