Kryptopyrroluria (KPU) is thought to be one of the most under-recognized conditions in the UK. Some estimates suggest the incidence of KPU to be as high as 80% in autism and between 40% and 70% in those with learning difficulties, ADHD, depression and bipolar disorders. What is KPU (HPU)? KPU, also known as HPU, (Haemopyrroluria),…