Turner syndrome is a genetic condition resulting from the partial or complete absence of an X-chromosome in phenotypic females. Individuals with Turner syndrome often display social difficulties that are reminiscent of those associated with autistic spectrum disorders (ASD), conditions associated with empathy and mirror-neuron system (MNS) deficits. The goal of the present study was (1) to investigate the extent to which adults with Turner syndrome display autistic and empathic traits, and (2) to probe the integrity of the MNS in this neurogenetic disorder. Sixteen individuals with Turner syndrome and 16 age-, sex-, and IQ-matched controls took part in a neuropsychological assessment where the Weschler Abbreviated Scale of Intelligence, the Autism Spectrum Quotient and the Empathy Quotient were administered. Functioning of the MNS was assessed by measuring motor cortex activity with transcranial magnetic stimulation during an action-observation task. Results show that individuals with Turner syndrome do not differ significantly from controls regarding autistic or empathic traits, and present normal functioning of the MNS during action observation. Correlational analysis showed a significant positive relationship between scores on the Empathy Quotient and motor facilitation during action observation, bringing further support to the hypothesis that MNS activity is related to sociocognitive competence.
Keywords: Autism; Empathy; Mirror neurons; Social cognition; TMS; X-chromosome.