Mutations cause autism and intellectual disability

Date: 16 February 2014

Introduction: Thanks to new technologies and international collaboration, researchers at the Centre of Medical Genetics (UAntwerp/Antwerp University Hospital) have discovered a new gene in which mutations may cause autism and intellectual disability.

About one percent of the population has an autism spectrum disorder (ASD). These disorders cause various behavioural problems and are sometimes associated with intellectual disability. Autism itself is characterised by limitations in communication and social interaction, along with a repetitive behavioural pattern.

Little is known about what causes autism, though there is some evidence that genetic factors play an important role. A cause can be pinpointed in only 15% of patients with autism, meaning that most patients and their families still have no idea what causes the disorder.

“Thanks to a new technology called Next Generation Sequencing, we can now unravel the DNA code for all of our 20 000 genes in just one experiment”, Céline Helsmoortel explains. “This allows us to identify many different mutations – or DNA errors – in patients with autism, but it is still very difficult to understand the impact of these mutations and whether or not they actually cause autism.”

As part of a pilot study, researchers at the Centre of Medical Genetics (UAntwerp/Antwerp University Hospital) analysed the genes of a small number of patients. In one patient, they found a mutation that switches off the gene for ANDP (activity-dependent neuroprotective protein). Previously, no link had been established between mutations in this gene and autism. Thanks to international collaboration and further research carried out in a larger group of autistic patients, nine other patients with mutations in the same gene were later identified.

“Mutations in ANDP may explain autism in 0.17% of patients, making it one of the most frequently recognised genetic causes of autism today”, says Frank Kooy. “Now, whenever a mutation is found in ADNP, doctors can immediately establish a diagnosis. Patients and their families only stand to benefit from this.” The researchers expect the new technology to lead to many more discoveries. Details about the research are published in Nature Genetics.