Brain dopamine-serotonin vesicular transport disease

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 352649

Definition

A rare infantile-onset neurometabolic disease characterized by dystonia, parkinsonism, nonambulation, autonomic dysfunction, developmental delay and mood disturbances.

Epidemiology

The prevalence is unknown. It has been described in 8 patients from one Saudi Arabian family to date.

Clinical description

Disease onset presents in infancy with hypotonia, loss of acquired head control and persistent crying and eye deviation. Motor development is delayed and later manifestations include severe parkinsonism, dystonia, ataxia, oculogyric crises, sleep and mood disturbances, temperature instability, excessive diaphoresis, ptosis and postural hypotension. Symptoms show no diurnal variation, do not improve with intake of vitamin B12 or folinic acid and worsened after administration of L-dopa.

Etiology

Brain dopamine-serotonin vesicular transport disease is caused by a mutation in the SLC18A2 gene (10q25), encoding the vesicular monoamine transporter 2 (VMAT2) which is responsible for the transport of dopamine and serotonin into synaptic vesicles. Mutations in this gene lead to the impairment of VMAT2 and consequently to problems with motor control, autonomic functioning and mood regulation.

Genetic counseling

It is inherited in an autosomal recessive manner, and genetic counseling is recommended.

Visit the Orphanet disease page for more resources.