Sequence analysis identified the spontaneous deletion of asparagine codon 139 or 140, through the deletion of CAA / ACA / AAC from the AACAACAA sequence at codong nucleotides 415-422. The deleted codon is located in the alpha-helical rod domain. This molecular lesion is the same that has been identified in Krt71Ca-Rin, Krt71Ca-9J, and Krt71Ca-10J.