Estimation of mutation rates from the number of rare alleles in a sample

To estimate the mutation rate from rare electrophoretic variants, a revised estimating equation is derived that takes into account the sampling distribution of the observed number of rare alleles in a sample drawn from the population. A check of the approximations used here suggests that the derived estimating equation is superior to the currently available one that is based on the expected number of rare alleles in the population. The new method is illustrated with a collation of electrophoretic data from literature. It is shown that the assumptions made in the theoretical treatment do not affect the estimate, per se, when the observed number of rare alleles is chosen as a statistic for estimating the mutation rates.