Hello, when I first came onto the sn boards 3 years ago, i started a thread called 'The bumpy road to diagnosis, anyone fancy holding hands?' My ds (who was then 10 months old) had just been assessed as being the developmental age of a 1 month old, and we were waiting for an MRI, bloods for genetics and lining up our first TAC meeting to sort out what support our child would need.
Ds is now nearly 4, he sat at 12-15 months, walked at 28 months, he has no speech, and is delayed in all areas. His MRI was normal, all his blood tests have been normal. It is still thought that he has a genetic condition, and he is part of 2 studies, one into a specific condition it is thought he might have and the other one is called the DDD study - Deciphering Developmental Delay (it is basically studying the DNA of 12,000 children with developmental delay, but no diagnosis, using the latest genetics technologies).
There are approx 50% of children with learning disabilities without a diagnosis, a large proportion of these are believed to have a genetic condition, but the world of genetics is so vast and new that the science hasn't caught up! There are 1000s of genetic conditions and chromosomal abnormalities possible, and despite using the most up to date technologies it can be very difficult to pinpoint one particular chromosmal aberration.
There is a great website called SWAN UK, (Syndromes Without A Name) which supports families with children who don't have a diagnosis, they have a very busy, friendly forum of parents and a lot of information about testing etc. Their website is here.
I have also found a lot of support here from parents of children with all sorts of special needs - whatever the diagnosis we are often going through similar things, and trying to get support for our children. There are some incredibly knowledgeable (and lovely and friendly) people on here!
I don't know if you would be interested in a 'hand holding' thread like the one i mentioned earlier, i found it incredibly helpful in the early days.
Ds may not have a diagnosis, but it is a lot clearer now what his needs are. He has complex health needs as well as learning difficulties, but he is sweet and funny and very despite not talking communicates with us through gesture and sign and just through his huge personality.