I’m one of the information and advice officers on the learning disability helpline. I have some brief information for this post, but do contact the helpline on 0808 808 1111 if you need more in depth advice.
There is information about different health professionals if you are concerned about your child here: https://contact.org.uk/media/1158641/concerned_about_your_child.pdf
Your GP would be best placed to make a referral to any specialist help. If you don’t feel that your GP is listening to your concerns you could ask to see a different one.
It’s always a good idea to think about evidence to support your concerns when you see the GP – a list of examples of things your child finds difficult, or simply a diary of a typical day or week. If you can get a letter of support from the school that would help too.
Your child’s teachers and the special educational needs co-ordinator (SENCO) are key in establishing evidence and finding out what works for him/her and what doesn’t to help him/her achieve the best educational and other outcomes. They can involve other professionals too, such as an educational psychologist.
If you still aren’t happy you could contact your local Healthwatch. They are the consumer champion for health and social care services in your area. You can ask about the referral pathway for getting a diagnosis for your child. Sometimes GPs aren’t aware of the details so it’s worth finding out and taking the info back to the GP if necessary.
I hope that helps,