PLXNA2 and Anxiety: Semaphorin-3A and Plexin-A2 are associated with different psychiatric disorders:69–72 Plexin-A2 is associated with schizophrenia, anxiety, and MDD72,73, while Semaphorin-3A is upregulated in the brain of schizophrenia patients and has been suggested to contribute to the synaptic pathology of the disorder70.