Figure 2  .

Difference in age at colectomy correlated with difference in macroscopic polyp count. Difference in age at colectomy is (age at colectomy of older sibling−age at colectomy of younger sibling). The y axis shows the log (older sibling macroscopic count/younger sibling macroscopic count). This method allows comparison within families with the same mutation and between families with different APC mutations; it shows that there was no significant trend for increasing numbers of polyps in the sibling who was older at colectomy.