Parkinson’s disease is a progressive neurological disorder that affects movement, cognition, and mood. It is caused by the loss of dopamine-producing neurons in the brain, which leads to tremors, stiffness, slowness, and other symptoms. The exact cause of Parkinson’s disease is unknown, but genetic factors play a role in some cases.
A rare mutation in the VPS13C gene
A team of researchers from Colombia, the United States, and Germany has discovered a new genetic mutation that causes Parkinson’s disease in a large Colombian family. The mutation is in the VPS13C gene, which is involved in the transport of proteins and lipids within cells. The mutation impairs the function of the VPS13C protein, resulting in the accumulation of toxic substances and the degeneration of neurons.
The researchers identified the mutation by sequencing the genomes of 102 members of the family, 32 of whom had Parkinson’s disease. They found that the mutation was present in all affected individuals, but not in the unaffected ones. They also confirmed the mutation in two other unrelated families from Colombia with Parkinson’s disease.
A novel animal model of Parkinson’s disease
To understand how the VPS13C mutation causes Parkinson’s disease, the researchers created a novel animal model of the disease by introducing the mutation into mice. They found that the mutant mice developed progressive motor and cognitive impairments, similar to the human patients. They also observed the loss of dopamine-producing neurons and the accumulation of alpha-synuclein, a protein that forms clumps in the brains of people with Parkinson’s disease.
The researchers also tested the effects of different drugs on the mutant mice. They found that levodopa, the standard treatment for Parkinson’s disease, improved the motor symptoms of the mice, but not the cognitive ones. They also found that rapamycin, a drug that activates a cellular pathway called autophagy, reduced the accumulation of alpha-synuclein and protected the neurons from degeneration.
Implications for diagnosis and treatment of Parkinson’s disease
The discovery of the VPS13C mutation adds to the growing list of genetic factors that contribute to Parkinson’s disease. The mutation is rare, but it affects a large number of people in Colombia, where it originated. The researchers estimate that about 1,000 people in Colombia carry the mutation, and that about 500 of them have Parkinson’s disease.
The researchers hope that their findings will help to improve the diagnosis and treatment of Parkinson’s disease, especially for the affected families. They plan to develop a genetic test to identify the mutation and to monitor its progression. They also plan to test the efficacy and safety of rapamycin and other drugs that target the VPS13C pathway in clinical trials.
The researchers also hope that their findings will shed light on the molecular mechanisms of Parkinson’s disease and pave the way for new therapeutic strategies. They believe that the VPS13C pathway is important for the maintenance of neuronal health and function, and that its dysfunction may contribute to other neurodegenerative disorders as well.
The study was published in the journal Nature Medicine.