A major class of cells called glial cells containing the fragile X mental retardation protein (FMRP), a discovery made by the McMaster researchers has strong implications for the cellular causes of Fragile X Syndrome (FXS), the most common genetic disorder associated with mental impairment. Brain development in the absence of FMRP leads to cognitive effects, learning and memory problems, attention deficit, hyperactivity, and autistic behaviours according to the report.
The researchers say that their discovery attains significance as the neuro-glial cells (astrocytes) play important roles in the development and maintenance of normal communication between neurons in the brain and spinal cord.
They say that the absence of FMRP in astrocytes may contribute to the abnormal neuronal structures seen in the brains of Fragile X patients.
“This is an unexpected finding. Like fitting a piece of a puzzle that suddenly paints the main picture in a different perspective. We have another major cell type as a focus in Fragile X research. It will supply needed insight on the biology causing Fragile X and help to strengthen the potential for treatment strategies,” says Laurie Doering, associate professor in the Department of Pathology and Molecular Medicine.
Until now, FMRP was thought to be found only in neurons.
But while studying the development of adult stem cells from the mouse brain, Laura Pacey, a Ph.D. student in Prof. Doering’s laboratory, realised that cells also produced the FMRP in addition to neurons.