Facial affect recognition deficit as a marker of genetic vulnerability to schizophrenia

The aim of this study was to investigate the possibility that affect recognition impairments are associated with genetic liability to schizophrenia. In a group of 55 unaffected relatives of schizophrenia patients (parents and siblings) we examined the capacity to detect facially expressed emotions and its relationship to schizotypal personality, neurocognitive functioning, and the subject's actual emotional state. The relatives were compared with 103 schizophrenia patients and 99 healthy subjects without any family history of psychoses. Emotional stimuli were nine black-and-white photos of actors, who portrayed six basic emotions as well as interest, contempt, and shame. The results evidenced the affect recognition deficit in relatives, though milder than that in patients themselves. No correlation between the deficit and schizotypal personality measured with SPQ was detected in the group of relatives. Neither cognitive functioning, including attention, verbal memory and linguistic ability, nor actual emotional states accounted for their affect recognition impairments. The results suggest that the facial affect recognition deficit in schizophrenia may be related to genetic predisposition to the disorder and may serve as an endophenotype in molecular-genetic studies. Keywords: affect recognition, genetics, cognition, schizophrenia, schizotypal personality El objetivo de este estudio era investigar la posibilidad de que el déficit para reconocer el afecto se asocie a la vulnerabilidad genética a la esquizofrenia. En un grupo de 55 familiares (padres y hermanos/as) no afectados de pacientes de esquizofrenia examinamos la capacidad para detectar emociones expresadas y su relación con la personalidad esquizotípica, el funcionamiento neurocognitivo y el estado emocional actual del sujeto. Se compararon los familiares con 103 pacientes esquizofrénicos y con 99 sujetos sanos sin ninguna historia familiar de psicosis. Los estímulos emocionales eran 9 fotos en blanco y negro de actores, quienes representaron las 6 emociones básicas, además de interés, desprecio y vergüenza. Los resultados revelaron déficit en reconocimiento afectivo en los familiares, aunque más leve que en los propios pacientes. No se detectó ninguna correlación entre el déficit y la personalidad esquizotípica medida con SPQ en el grupo de familiares. Ni el funcionamiento cognitivo, incluyendo la atención, la memoria verbal y la habilidad lingüística, ni tampoco los estados emocionales actuales explicaron el déficit en el reconocimiento del afecto. Los resultados sugieren que el déficit en reconocimiento de afecto facial en la esquizofrenia puede relacionarse con una predisposición genética al trastorno y puede servir de endofenotipo en los estudios moleculares genéticos. Palabras clave: reconocimiento de afecto, cognición, esquizofrenia, personalidad esquizotípic

Interaction Effects of Season of Birth and Cytokine Genes on Schizotypal Traits in the General Population

Literature suggests that the effect of winter birth on vulnerability to schizophrenia might be mediated by increased expression of proinflammatory cytokines due to prenatal infection and its inadequate regulation by anti-inflammatory factors. As the response of the immune system depends on genotype, this study assessed the interaction effects of cytokine genes and season of birth (SOB) on schizotypy measured with the Schizotypal Personality Questionnaire (SPQ-74). We searched for associations of IL1B rs16944, IL4 rs2243250, and IL-1RN VNTR polymorphisms, SOB, and their interactions with the SPQ-74 total score in a sample of 278 healthy individuals. A significant effect of the IL4 X SOB interaction was found, p=0.007 and η2=0.028. We confirmed this effect using an extended sample of 373 individuals. Homozygotes CC born in winter showed the highest SPQ total score and differed significantly from winter-born T allele carriers, p=0.049. This difference was demonstrated for cognitive-perceptual and disorganized but not interpersonal dimensions. The findings are consistent with the hypothesis that the cytokine genes by SOB interaction can influence variability of schizotypal traits in the general population. The IL4 T allele appeared to have a protective effect against the development of positive and disorganized schizotypal traits in winter-born individuals