Figure 1.

Compilation of all of the mutations affecting the two principal SHH domains sorted by their position and category. A: deletions or insertions that retain frame occur most commonly in critical regions (red colored bars) but also non-conserved regions of unknown importance (black colored bars; see also Fig. 2); selected missense alterations (thin arrows) that occur in the signal peptide, palmitate addition region, cholesterol addition site are presented here to imply their likely effect on processing. B: nonsense and frameshift mutations truncate SHH-N or affect domains required for protein intein-like splicing or cholesterol addition. C: missense alterations (thin arrows) occur equally in both domains; however, the distribution of mutations is non-random and preferentially occurs within conserved domains (see Table 2).