Impact of POT1 splice acceptor site mutation on splicing. (A) Splice acceptor site consensus scores predicted by MaxEntScan²⁴  for each base from the natural POT1 intron 13/exon 14 boundary across exon 14. For clarity, only part of the intron (lower case text above black line) and exon (upper case text above black box) are shown. The predicted score for the unmutated natural splice site (red bar) is also labeled. Positive scores are otherwise marked in blue and negative scores in peach. (B) MaxEntScan splice acceptor consensus scores for the same region based upon the sequence of c.1164-1G>A POT1 mutation carriers. The scores of the mutated natural splice acceptor (pink bar) and the predicted alternative splice site with the highest MaxEntScan score (43 bp downstream) are labeled. The part of exon 14 that would be removed by use of this splice site is indicated by a gray box. (C) Abnormal splicing product detected by RT-PCR using cDNA from a CLL case (Ca) carrying the c.1164-1G>A mutation. This product is absent from control (Co) cDNA. bp, base pairs; L, ladder; NT, no template reaction.