- Researchers at Johns Hopkins School of Medicine and collaborators conducted gene studies in people with MS who had been tracked in various studies using visual function tests and optical coherence tomography (OCT), which detects the health of nerves at the back of the eye.
- The team identified gene variants related to the activation of “complement,” a family of immune system proteins that appear to be linked to more severe nerve loss and worsening of eye tests.
- This identifies for the first time gene variations linked to the severity of MS disease in the visual system and provides new insights into the underlying causes of MS damage.
- The team, led by Peter Calabresi, MD, published results online July 9, 2019 in the journal Brain. This study was supported in part by a National MS Society postdoctoral fellowship to Kathryn Fitzgerald, DSc.
Multiple sclerosis, an immune system-mediated disease that attacks the brain, spinal cord and optic nerve, occurs in individuals whose genes make them more susceptible to a combination of environmental and other factors that trigger MS. MS may be mild or severe, for reasons that are not yet clear. Using advanced gene-chip technology to conduct large-scale gene scans called genome-wide association studies (GWAS), which can identify genetic variants associated with MS. More than 200 gene variations have been identified that can increase a person’s risk of getting MS. However, so far research has been inconsistent in terms of identifying genes that may influence how severe the disease may become in an individual.
OCT (optical coherence tomography) is an imaging tool that can scan the condition of nerve layers at the back of the eye. Extensive research using OCT, and an eye test called low-contrast letter acuity, has suggested that specific types of thinning of nerves and results of low-contrast letter acuity tests in people with MS can predict future disease progression.
A team of researchers at Johns Hopkins School of Medicine and collaborators across the country decided to conduct GWAS in people with MS who had been tracked as participants in various studies using OCT and other measures for an average of over 3 years. The team was looking for gene variants that might be linked to, and possibly predict, more severe nerve loss and worsening of eye tests.
Through this extensive series of studies, the team identified the involvement of gene variations that control the early activation of “complement” – a family of immune system proteins known to help the immune system kill foreign invaders, such as bacteria, and more recently identified as playing a role in nervous system damage and progression in MS. Specifically, the team found that “C3” was strongly associated with nerve thinning seen on OCT, and “C1QA” and “CR1” were strongly associated with loss of low-contrast visual acuity.
The team, led by Peter Calabresi, MD, published results online July 9, 2019
in Brain. This study was supported in part by a National MS Society postdoctoral fellowship to Kathryn Fitzgerald, DSc.
This work identifies, for the first time, gene variations linked to the severity of MS disease in the visual system and provides new insights into the underlying causes of MS damage. Additional research is needed to further verify these results and understand how this finding may be used to predict disease progression and severity, and whether components of complement may be a target for the development of future therapies.
Read more about vision problems in MS