Deep sequencing reveals low-level mutant clones. (A) After deeper sequencing at 450× coverage for 96 patients, an additional 4 mutations were identified, which were present at between 3% and 6.3% RMA within total bone marrow DNA. One of these mutations was found in a patient with an additional mutation, which had previously been identified. Means and standard deviations for RMA corresponding to 3 independent experiments are shown. (B) Representative sequence readout for 1 of these mutations is exampled and shows an A>G substitution, denoted by the prominent black bar, in 6% of sequence reads (6% variation from the reference sequence, left axis), leading to a Q1414H nonsynonymous amino acid change. The sequence depth is 820× across this region traced by the gray line running across the top of the graph. Experimental noise accounts for ≤ 1% of variation.