PTEN and autism spectrum disorder: Mitochondrial dysfunction is also closely associated with neurodevelopmental disorders, particularly autism spectrum disorder (ASD) (10, 11) and genetic syndromes closely associated with ASD including mechanistic target of rapamycin (mTOR) (12–15); phosphatase and tensin homolog (PTEN) (16) and WDR45 (17) mutations; Rett (18–20), Phelan–McDermid (21), Angelman (22), and Down (23, 24) syndromes; as well as 15q11-q13 duplication (25, 26) and septo-optic dysplasia (27).