No lesion has been identified in the protease domain. Northern and Southern analysis indicated that DNA is missing DNA from the 3' region of ndl, and the encoded RNA is truncated. Sequencing revealed a deletion of 569bp near the 3' end of the coding sequence, which would cause a frame shift leading to omission of the 402 C-terminal residues of the wild-type protein.

569bp deletion causes a frameshift during translation that truncates the follicle cell-specific transcript.