VPS35 and hyperinsulinemic hypoglycemia, familial, 4: The conditional VPS35 D620N knock-in (KI) model obtained from VPS35 D620N KI mice characterized by Cataldi et al. [138] crossed with mice from the Sox2-Cre-delete line results in motor deficiency after 14 months in the open field and narrow beam tests, along with a significant decrease of DA neurons in the SN and fibers in the striatum compared to control.