Quantitative autism traits in first degree relatives

...evidence for the broader autism phenotype in fathers, but not in mothers and siblings

SAGE journal — Abstract

Autism spectrum disorder (ASD) symptoms are present in unaffected relatives and individuals from the general population. Results are inconclusive, however, on whether unaffected relatives have higher levels of quantitative autism traits (QAT) or not. This might be due to differences in research populations, because behavioral data and molecular genetic research suggest that the genetic etiology of ASD is different in multiplex and simplex families. We compared 117 unaffected siblings and 276 parents of at least one child with ASD with 280 children and 595 adults from the general population on the presence of QAT using the Social Responsiveness Scale (SRS). Mean SRS scores for siblings, control children, parents and control adults were 25.4, 26.6, 33.7 and 32.9. Fathers of children with ASD showed significantly higher levels of QAT than controls, but siblings and mothers did not. We could not detect a statistically significant difference in SRS scores between relatives from simplex and multiplex families. These results do not support the theory of differential (genetic) etiology in multiplex and simplex families and suggest that a carried genetic risk is generally not expressed phenotypically in most relatives, except in fathers.

Wouter De la Marche

1. Child and Adolescent Psychiatry Department and Leuven Autism Research, UPC-K.U.Leuven, Leuven, Belgium

1. Ilse Noens

1. Parenting and Special Education Research Group and Leuven Autism Research, K.U.Leuven, Leuven, Belgium and Psychiatric and Neurodevelopmental Genetics Unit, Massachusetts General Hospital, Boston, MA, USA

1. Jan Luts

1. Department of Electrical Engineering (ESAT), Research Division SCD, K.U.Leuven, Heverlee, Belgium

1. Evert Scholte

1. Clinical Child and Adolescent Studies, Universiteit Leiden, Leiden, the Netherlands

1. Sabine Van Huffel

1. Department of Electrical Engineering (ESAT), Research Division SCD, K.U.Leuven, Heverlee, Belgium and Leuven Autism Research, K.U.Leuven, Leuven, Belgium

1. Jean Steyaert

1. Child and Adolescent Psychiatry Department and Leuven Autism Research, UPC-K.U.Leuven, Leuven, Belgium and Clinical Genetics, University Hospital Maastricht, Maastricht, the Netherlands

1. Jean Steyaert, Child and Adolescent Psychiatry Department, UPC-K.U.Leuven campus Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium. Email:jean.steyaert@med.kuleuven.be