Brain Dopamine–Serotonin Vesicular Transport Disease and Its Treatment

Known disorders of biogenic amine neuromediators (dopamine, norepinephrine, epinephrine, and serotonin) involve defects in nine enzymes1-9 and one transporter.10 Affected persons present in early childhood with symptoms referable to the affected neurotransmitter, and the disorders are diagnosed by measurement of neurotransmitter breakdown products in the cerebrospinal fluid (CSF). A deficiency in dopamine results in movement disorder; deficient norepinephrine or epinephrine causes autonomic dysfunction; and serotonin deficiency leads to sleep and psychiatric disturbances.2,3,6
We describe members of a family with symptoms of deficiencies in dopamine (dystonia, parkinsonism, and oculogyric crises), serotonin (sleep and mood disturbance), and epinephrine and norepinephrine (diaphoresis, temperature instability, ptosis, and postural hypotension), with no demonstrable deficiency of neurotransmitters in the CSF. Genome investigation revealed a mutation in the gene encoding VMAT2 that compromises transport of biogenic amines into synaptic vesicles, resulting in impairment of their synaptic transmission without detectable reductions in their amounts.

 Brain Dopamine–Serotonin Vesicular Transport Disease and Its Treatment