A Saudi Arabian family was found to have a genetic mutation leading to symptoms similar to parkinson’s disease, but the normal tests for the disease indicated otherwise. Researchers of the University of Toronto found that using a dopamine agonist reversed this parkinsonian condition almost completely.
Of this family, eight children, with a 16 year old as the eldest, were found to have symptoms of brain dopamine-serotonin vesicular transport disease, a VMAT2 deficiency. VMAT2 is a transporter protein that escorts dopamine across the neuronal synapse to its receptor.
Dopamine, in this context, serves as a way for neurons to communicate signals to each other. This was the mechanism breaking down in these children. The children’s symptoms from not having this neurotransmitter transporter were slow walking, difficulty initiating movement, droopy eyelids, audible breathing, dystonia, and other dopamine deficiency signs.
Through analysis of single nucleotide polymorphisms (SNPs pronounces “snips”) a mutation of the SLC18A2 gene was found as the cause of the VMAT2 absence.
To treat, the children were given a compound that activates dopamine receptors, a dopamine agonist, in hopes of making up for the neurotransmitters not hitting their marks. The compound was pramipexole. In less than seven days, improvement was seen. The jerky movements, trouble walking, and accompanying symptoms were almost completely gone after treatment.
The dopamine agonist was shown to nearly reverse all symptoms of the congenital dopamine transporter disease. Dopamine has proven once again how essential it is to the living system.
Jennifer J. Rilstone, Reem A. Alkhater, Berge A. Minassian. Brain Dopamine–Serotonin Vesicular Transport Disease and Its Treatment. The New England Journal of Medicine, 2013.