Peter the Wild Boy. From the Parish Register of Northchurch in Hertford

Story of Peter the Wild Boy who was found living wild in the forest of Hertswold near Hanover, wearing the remains of a shirt collar, and brought to England to be cared for on the orders of Princess Caroline. He lived with the Fenn family who were farmers in the parishes of Northchurch and Broadway in Hertfordshire. The pages contain a long analysis and description of his medical condition which included no ability to speak, a degree of learning difficulty which bore no physical trace, having two fingers webbed together, the ability to hum a tune, the ability to express emotions and being of a gentle nature.
The article also refutes many rumours about his physical appearance and behaviour that had been published and states that the article was written by someone who knew him well. Research at Hertfordshire Archives and Local Studies Centre indicates that the author of the piece was the local school master who would presumably have known Peter.
Peter died in 1785 being around 72 years of age and a brass plate was put up in his memory inside the church.
The wikipedia entry for 'Peter the Wild Boy' attributes his condition to Pitt–Hopkins syndrome, based on a portrait of him by William Kent which hangs in Kensington Palace. However this description suggests no facial abnormalities and the wording of this text could be describing classic autism.