Sonstegard et al (2013) investigated the lethal Jersey haplotype, namely haplotype JH1 on chromosome BTA15 (see Mapping section). They first refined the haplotype "to a 15-marker window (15,162,470 to 15,949,175)" and then obtained whole-genome sequence from 11 bulls carrying this haplotype. Analysis of the sequence of these carriers in the candidate region revealed a "high-impact stop-gain SNP located at position 15,707,169 on BTA15. This C-to-T transition SNP results in an Arginine to a stop codon in exon 3 of CWC15, the bovine protein CWC15 homolog of a spliceosome-associated protein . . . . This nonsense mutation would reduce the size of the CWC15 protein product from 231 amino acids in length to only 54 amino acids. A NCBI conserved domains search on the bovine CWC15 protein product reveals that this truncated protein would not have the conserved Cwf_Cwc_15 (pfam04889) domain present in the wildtype."