Reelin

Derived from an abnormal reeling gate, it is a protein in the brain.  Originally found in reeler mice who manifest this gait, they were shown to have to have deficiency in this protein and were homozygous for the reel in gene.  In contrast, mice heterozygous for the gene had no obvious neuroanatomical defects, but those that had showed behavior that resembled schizophrenia. 

See Ataxia, 2q11 (CATCH 22) deletion syndrome, Cell migration, Hox genes, Proteins