PTEN and autism spectrum disorder: PTEN germline mutations are among the most common causes of autism spectrum disorder (ASD), accounting for approximately 2% to 5% of cases,4,5 yet originally identified in a subset of relatively rare syndromes predisposing to breast, thyroid, and other cancers.6 The PTEN-related ASD-cancer phenotypic dichotomy and inability to preemptively estimate disease outcomes pose a challenge for more timely and precise clinical management.