A rare genetic intellectual disability syndrome characterized by global developmental delay, intellectual disability, severe speech delay, behavioral abnormalities (including impulsivity, compulsivity, stubbornness, manipulative behaviors, temper tantrums, and aggressive behaviors), autism spectrum disorder and mild and variable dysmorphic facies (including deep-set eyes and a prominent nasal septum, extending below the alae nasi) due to point mutation of USP7 gene or 16p13.2 microdeletion where USP7 is completely or partially deleted. Behavioral abnormalities are more pronounced in microdeletion. Patients may also have hypotonia, feeding problems, delayed walking with unsteady gait, hypogonadism in males, seizures and ocular anomalies (such as myopia, estropia, strabismus, and nystagmus).