Approximately 200bp deletion, plus insertion of 4 nucleotides (CTGA), within the 3' region of the Scm transcription unit, at the 3' end of the ORF. The C-terminal 49 amino acids of Scm protein, including most of the SPM domain, are removed and replaced by 26 novel amino acids encoded by extension of the open reading frame into the 3' UTR. Deletion of the C-terminal 49 amino acids.