I wonder if this is related to neurite repulsion. In Drosophla, the DSCAM gene is alternatively spliced to provide an "expression signature" for each neuron so

I wonder if this is related to neurite repulsion. In Drosophla, the DSCAM gene is alternatively spliced to provide an "expression signature" for each neuron so they can maintain neurite repulsion. Maybe these point mutations are providing a similar function?