NRXN1 and apraxia: 2013). All carriers presented a cognitive profile characterized by dysexecutive syndrome with symptoms similar to the adult probands, in the absence of aphasia, amnesia, agnosia, and apraxia. The NRXN1 deletion affects cognitive traits in all carriers suggesting that these CNVs could have variable expressivity instead of incomplete penetrance. This hypothesis is in accordance with a recent study that conducted neuropsychological and psychiatric examinations. The neuropsychiatric CNVs carriers showed cognitive abilities between those of normal controls and ID patients (Stefansson et al. 2014).