SNCA and Parkinson disease: VPS35 heterozygote mice (VPS35+/−) exhibit dopaminergic neuron loss and an increase in alpha synuclein expression, whilst mice expressing a deletion of VPS35 specifically in their dopaminergic neurons have a stronger phenotype displaying an enhanced reduction of dopaminergic neurons, increased alpha synuclein expression and motor deficits, all hallmarks of PD [25].