IgLON5 antibody syndrome first came to my attention in a paper from Lancet Neurology titled A novel non-rapid-eye movement and rapid-eye-movement parasomnia with sleep breathing disorder associated with antibodies to IgLON5. A passing phenomenon I thought, but added it to neurochecklists anyway.
I then came across another paper in Neurology 2015 expanding the phenotype titled Sleep disorder, chorea, and dementia associated with IgLON5 antibodies. And another paper from Journal of Immunology practically established this as a real, and not a phantom, phenomenon. The paper is titled Chorea and parkinsonism associated with autoantibodies to IgLON5 and responsive to immunotherapy.
So what is IgLON5? Well its a neuronal cell adhesion protein. Naturally. The key features of the syndrome are:
- Sleep-related breathing problems
- Rapid eye movement (REM) sleep behaviour disorder
We are surely going to hear more of this antibody syndrome. Watch this space!