Immunology

A scientific study published on the journal Molecular Psychiatry identifies new genes involved in autism, a polygenic disorder that is difficult to diagnose and treat. Autism spectrum disorders (ASDs) represent a group of neurodevelopmental disorders which affect one out of 80-100 children. Autism's aetiology remains mainly unknown but there is strong evidence that genetic factors play a major role. An active international research has been carried out for several years in order to identify candidate genes which explain the origin and development of the disease.

Looking for new candidate genes

Researchers who participated in the research are: Bru Cormand, Claudio Toma, Bàrbara Torrico and Alba Tristán, from the Department of Genetics and the Institute of Biomedicine of the University of Barcelona (IBUB), affiliated centres with the campus of international excellence BKC; Concepció Arenas (Department of Statistics of the UB) and Mònica Bayés, researcher from the National Centre for Genome Analysis (CNAG), located at the Barcelona Science Park (PCB-UB), and the groups led by Amaia Hervás, coordinator of the Child and Adolescence Mental Health Unit at the Mutua de Terrassa University Hospital, and Marta Maristany, from Sant Joan de Déu University Hospital, affiliated centres with the campus of international excellence HUBc.

Bru Cormand, head of the Research Group on Neurogenetics at the Department of Genetics of the UB, affirms that "studies made with monozygotic (genetically identical) and dizygotic twins show that genetic factors play a major role in the aetiology of the disease". Therefore, "if a monozygotic twin has autism, the likelihood that the other twin also has the disease is 60-90%; however, if they are dizygotic twins, the probability is reduced up to 20%", states the expert. This proves that genetic factors play a major role in the aetiology of the disease, but the association between the disease and one person's set of mutated genes remains uncompleted.

Inherited mutations in autism: a new perspective

To date, studies on autism genetics were mainly focused on de novo mutations â€"the ones that appear in a child but they are not present in progenitorsâ€" in families with one child affected. However, the work published on Molecular Psychiatry and first signed by the expert Claudio Toma provides an innovative view on the study of ASDs genetics: "It is the first time that mutations transmitted to children by any of the progenitors are studied in a genomic perspective. In total, ten families in which two or three children have autism were analysed", details Bru Cormand.

The research is based on whole exome sequencing (WES), which is the part of the genome translated into proteins. This innovative and quite recent technique is a really effective strategy to diagnose hereditary diseases. The study, which has identified more than 200 rare variants inherited by children, determines that genes YWHAZ and DRP2, among others, are new candidates in the research on autism genetic basis.