As we have clustered mutations, we need to define a map σ which relates individual mutations to their respective cluster.
By tracing subtle differences in mutations among rat populations, the scientists identified where different rat families had clustered.
One hypothesis is that older first-time mothers are more likely than younger first-time mothers to already have breast tissue with cells carrying cancer-causing mutations, or to have clusters of abnormal precancerous cells.
However, more direct functional associations of APOBEC family member(s) proteins with clustered mutations have to be carrying out.
More than 80 different disease-causing mutations have been identified, mostly clustered in exon 3 but also found in exons 4 and 6, either arising de novo or transmitted in an autosomal-dominant manner (1, 2).
The second feature is the subdomain predictor of whether a given mutation falls within the N-terminal or the C-terminal lobe, since disease mutations have a tendency to cluster within the C-terminal lobe rather than the N-terminal lobe.
Only three mutations have been described to date, all clustered in the N-terminus of the protein: p.Ala7Val, p.Ala9Val and p.Ala33Pro (Lee et al., 2004; Rainier et al., 2004; Chen et al., 2005; Djarmati et al., 2005; Hempelmann et al., 2006; Ghezzi et al., 2009).
The implication is that these clusters of mutations have not all occurred in a single event.
These mutations have a particular pattern, as they are generally clustered in one or more regions along the protein.
However, over 100 other rare mutations have been described, most of which cluster to the glycine-rich loop and activation segment in the kinase domain.
