This ENU-induced mutation was isolated in a screen at the University of Pittsburgh. The molecular lesion is a T to C substitution at coding nucleotide 197 in exon 3 of the cDNA (c.197T>C, NM_027725). This changes the leucine residue to a proline at position 66 of the encoded protein (p.L66P). Additional incidental mutations were detected in sequencing for the causative mutation, Daw1b2b1584Clo, and may be present in stocks carrying this mutation.