What’s New in Psychology?

A New Genetic Disease Causing Learning Problems Identified   

Jim Windell

           It is likely that you or some other person reading this article has a rare disease. The fact is that one in every 17 people will suffer from a rare disease at some time in their lives. Often rare diseases show up in children and affect some aspect of their growth and development.

           Most of these rare diseases have a genetic cause, but proving which gene change causes a disease is a huge challenge. 

           Professor Matt Guille, a professor who leads a laboratory in the Epigenetics and Developmental Biology research group at the University of Portsmouth in Portsmouth, England, is a co-author of a new study that identifies a new genetic disease. The study was recently published in the American Journal of Human Genetics.

           The new genetic disease, which causes some children’s brains to develop abnormally, results in delayed intellectual development. A majority of people with the condition have severe learning difficulties which affect their quality of life. However, the disease is so new it doesn’t have a name yet. An international team of researchers from the universities of Portsmouth, Southampton and Copenhagen have discovered that changes in a protein coding gene called Glutamate Ionotropic Receptor AMPA Type Subunit 1 (GRIA1) causes this rare genetic disease.

             Dr. Guille indicates that previously while studies connecting a gene and a disease were mainly performed in mice, several labs, including his own at the University of Portsmouth, have recently shown that experiments in tadpoles can also provide very strong evidence about the function of variant human genes. The process of re-creating some gene variants in tadpoles is straightforward and can be done in as little as three days. 

           According to Guille, “We are currently extending and improving our technology in a program funded by the Medical Research Council; this is making it applicable to the wider range of disease-related DNA changes provided to us by our clinical collaborators.”

           The GRIA1 gene helps to move electrical signals around the brain. However, if this process is interrupted or made less efficient, it can cause a reduction in the brain’s capacity to retain information. The research team, made up of frog geneticists, biochemists and clinical geneticists, used tadpoles in which the human gene variants were mimicked using gene editing to show that GRIA1 changes are the underlying cause of the behavior-altering disease. The biochemical analysis of the variants was also performed in frog oocytes.

           Guille adds that, “Next generation DNA sequencing is transforming our ability to make new diagnoses and discover new genetic causes of rare disorders. The main bottleneck in providing diagnoses for these patients is linking a change discovered in their genome firmly to their disease. Making the suspect genetic change in tadpoles allows us to test whether it causes the same illness in humans. The resulting data allow us to support our colleagues in providing the more timely, accurate diagnosis that patients and their families so desperately need.”

            Co-author Dr Annie Goodwin, Research Fellow at the University of Portsmouth who performed much of the study, says that, “This was a transformational piece of work for us; the ability to analyze human-like behaviors in tadpoles with sufficient accuracy to detect genetic disease-linked changes opens the opportunity to help identify a huge range of diseases. This is particularly important given that so many neurodevelopmental diseases are currently undiagnosed.”

             Now that the variant for this new disease has been identified, it will help clinicians come up with targeted interventions to help patients and their families, also opening the door to screening and prenatal diagnosis. It also may end the diagnostic odyssey as patients and families try to get answers about the disorder.

            To read the original article, find it with this reference:

Vardha Ismail, Linda G. Zachariassen, Annie Godwin, Mane Sahakian, Sian Ellard, Karen L. Stals, Emma Baple, Kate Tatton Brown, Nicola Foulds, Gabrielle Wheway, Matthew O. Parker, Signe M. Lyngby, Miriam G. Pedersen, Julie Desir, Allan Bayat, Maria Musgaard, Matthew Guille, Anders S. Kristensen & Diana Baralle. (2022). Identification and functional evaluation of GRIA1 missense and truncation variants in individuals with ID: An emerging neurodevelopmental syndrome. The American Journal of Human Genetics, 109(7), 1217-1241.

ISSN 0002-9297; https://doi.org/10.1016/j.ajhg.2022.05.009.