Paediatricsmiddle twist
An 18-month-old boy is brought back to the general practice by his father. At his 15-month check he was walking, waving goodbye, using eight words and handing his father the television remote. Over the past two months he has stopped waving, now says only "dada", and no longer looks up when he is called; he has become quiet and hard to engage. He walks normally, has no dysmorphic features, and his head circumference remains on the 50th centile. Which one of the following is the most appropriate action?