Parents who have one child with autism would like a genetic test to predict their next child’s risk of the disorder. But it’s not clear how well the tests work.

A genetic panel intended to predict the risk of developing autism debuted for clinical use in April, while another is in commercial development and a third was published in Molecular Psychiatry in September. But some experts are concerned, saying the tests are based on preliminary scientific evidence.

People with autism are twice as likely as controls to have mutations that disable both copies of a gene, according to preliminary research presented Wednesday at the Autism Consortium Research Symposium in Boston.

Individually, common genetic variants confer little risk for autism. But taken together, they may contribute significantly, predicts a statistical analysis published 15 October in Molecular Autism.

About 1 in 500 children referred to genetic testing for undefined developmental delay, intellectual disability, or autism have duplications of the 15q11-13 chromosomal region, according to a new analysis. That makes the region the second most common large genetic alteration linked to autism.

Researchers are beginning to tease apart how dosage of genes within the 15q11-13 chromosomal region contributes to autism symptoms.

Parents enroll their children in genetic research studies because of the opportunities to meet other families in the same situation, take control of their circumstances, and validate the medical nature of their child’s condition, according to a report published 11 July in the Journal of Autism and Developmental Disorders.

Several scientists at the Phelan-McDermid Syndrome Foundation’s annual meeting focused on the wide range of symptoms, including a sudden loss of motor and cognitive skills, that seem to crop up in adults with the disorder.

Researchers have found deletions and duplications of a small piece of chromosome 2 in individuals with autism, developmental delay, epilepsy or attention deficit hyperactivity disorder.

Large-scale swapping of genetic material between chromosomes may play an important role in autism, according to a study published 27 April in Cell.