This is a recessive ENU mutation identified in a screen for morphological abnormalities appearing at E9.5. Exon 16 of the gene has been skipped in the transcripts from this hypomorphic allele, owing to a splice site mutation that changes exon/intron 16 splice donor site G-GT to G-GC, resulting in an in-frame deletion of 29 amino acids in the encoded peptide. This results in the loss of 1 out of 10 tetratricopeptide repeats. (J:86437)