A new genomic study of families whose members had ADHD showed they all had specific features in certain genes. The identification of such patterns may help improve the diagnosis of ADHD. The research was conducted by a team from I.M. Sechenov First Moscow State Medical University, together with foreign colleagues and the results were published in Molecular Psychiatry. Genetically based diagnosis of ADHD could provide earlier detection and treatment. This is especially critical now that 10% of children in the U.S. are being diagnosed with ADHD.
Recent research has appeared to show that the causes and progression of ADHD are governed by a combination of environmental (e.g., stress or illness of the mother during pregnancy, complications during labor, or diseases suffered in early childhood) and genetic factors. The pathological mechanisms behind ADHD are currently still not known.
Evgeniy Svirin, a research associate on the study, said “We believe the development of ADHD may be caused by alterations in the structure of genes encoding proteins which participate in signal transmission in the nervous system using special biologically active substances—neuromediators. In the case of ADHD, the changes affect, among others, serotonin and dopamine pathways in the nervous system that play an important role in the processes of attention, motivation, and learning. The disorder has a complex genetic nature that hasn’t been addressed until recently.”
The scientists studied the rare functional variants in whole set of genes in several generations of families with ongoing occurrences of ADHD. In particular, they traced the activation patterns for two genes:
AAED1 – This protein produced by this gene binds with several other proteins that participate in dopamine and glutamate transmission. Changes in its activity can potentially influence the excitability of some structures of the central nervous system leading to behavioral alterations.
ATAD2 – The function of this gene is currently unknown, but was highly associated with ADHD.
These rare variants have also been discovered in ADHD patients not associated with the studied families and provide additional evidence for considering them as ADHD risk genes.The study results offer the potential for these genes to be used for the development of genetically based diagnostics methods for ADHD.