PT - JOURNAL ARTICLE AU - Ester Coutinho AU - Leslie Jacobson AU - Marianne Giørtz Pedersen AU - Michael Eriksen Benros AU - Bent Nørgaard-Pedersen AU - Preben Bo Mortensen AU - Paul J Harrison AU - Angela Vincent TI - CASPR2 autoantibodies are raised during pregnancy in mothers of children with mental retardation and disorders of psychological development but not autism AID - 10.1136/jnnp-2016-315251 DP - 2017 Sep 01 TA - Journal of Neurology, Neurosurgery & Psychiatry PG - 718--721 VI - 88 IP - 9 4099 - http://jnnp.bmj.com/content/88/9/718.short 4100 - http://jnnp.bmj.com/content/88/9/718.full SO - J Neurol Neurosurg Psychiatry2017 Sep 01; 88 AB - Background, Methods and Objectives Maternal autoantibodies to neuronal proteins may be one cause of neurodevelopmental disorders. This exploratory study used the Danish archived midgestational sera and their nationwide registers to search for antibodies to the N-methyl-D-aspartate receptor (NMDAR) and contactin-associated protein-like 2 (CASPR2) in maternal sera, and to relate them to subsequent psychiatric diagnoses in the woman or her child.Results In a sample of 192 women, there was no association between antibody status and subsequent psychosis in the mothers. However, NMDAR antibodies (n=4) or CASPR2 antibodies (n=1) were identified in 5/11 (45.5%) women whose children were given a diagnosis of mild or unspecified mental retardation or disorders of psychological and motor development (collectively abbreviated as mental retardation and/or disorders of psychological development (MR/DPD)) compared with 9/176 (5.1%) of the remaining mother (p<0.001). These findings were followed up in a specifically selected cohort, in which CASPR2 antibodies were detected in 7/171 (4.1%) mothers of MR/DPD progeny, compared with only 1/171 (0.6%) control mother (p=0.067). The combined sample showed a significantly higher frequency of CASPR2 antibodies in mothers of MD/DPD children (p=0.01). These autoantibodies were not increased in mothers of children with autistic spectrum disorder.Conclusions These findings complement the known roles of CASPR2 in brain development, and warrant further epidemiological and experimental studies to clarify the role of CASPR2 and possibly other antibodies in neurodevelopmental disorders.