Great attempts have been made not to duplicate sequences in the Concordance, as this can affect the reporting of relative substitution frequencies. Inconsistencies exist between the number of sequences that appear in the published literature on a given population and the number of sequences that have been submitted to GenBank for that population. It is, nonetheless, confusing. Care has been taken to reconcile numbers of sequences in the literature with numbers of sequences in GenBank. However, the GenBank accession numbers provided may not accurately reflect the numbers of individuals originally reported.
All sequences appear in their original forms, and ambiguities generally represent sequencing errors.
A list of these is being compiled, and will appear in a future edition. There remain instances where non-standard symbols are used.