Intellectual asymmetry and genetic liability in first-degree relatives of probands with schizophrenia.

Intellectual asymmetry with superiority of verbal skills to spatial skills frequently characterises patients with schizophrenia, but it is unclear whether this pattern also reflects genetic susceptibility to the disorder. We examined the association of a continuous measure of genetic liability to schizophrenia with Verbal-Spatial Contrast IQ (an index of intellectual asymmetry) in 108 first-degree relatives without psychosis of probands with schizophrenia. Higher genetic liability was significantly associated with greater intellectual asymmetry in favour of verbal skills. Intellectual asymmetry with a relative superiority of verbal skills to spatial skills represents a putative endophenotype of schizophrenia.