PTEN and attention deficit-hyperactivity disorder: It must be noted, however, that the heterogeneity of age in our patients may have limited the ascertainment of some phenotypic characteristics, including many PTEN-associated neoplasms, either benign or malignant in nature, which are not expected in childhood, and some neurodevelopmental and behavioural anomalies, such as speech delay and ADHD, which cannot be properly assessed in the very first years of life.