Figure 5

Suspected splicing pathways of the region encompassing exons 6 to 10. Schematic representation of exon 8 and its splice sites is given on the top of the figure. The effectiveness of the donor and acceptor splice sites were determined using the webgene program http://itba.cnr.it/webgene/ and is indicated above the sequence. A cryptic acceptor splice site is used in the case of the IVS6-1g->t mutation (described in [35]). Exons are represented by boxes and introns by lines. The thick arrow is the major splicing pathway, whereas thin arrows are minor alternative splicing pathways. We suggest that del231 could be explained by the fact that intron 8 is spliced out before introns 7 and 9, leading to an intermediate in which exons 8 and 9 are defined together. Because of exon 8 weak definition, a minority of transcripts eliminates both exons 8 and 9. Del100 could be produced by another minor splicing pathway, in which exon 8 is skipped alone.