Fig. 8

Repeat length distribution using the PacBio no-amplification (No-Amp) targeted sequencing method. We sequenced sample 1 using the PacBio no-amplification (No-Amp) targeted sequencing method and obtained 828 circular consensus sequences. Approximately 70% (576 of 828) of reads covered the individual’s wild-type allele (two repeats), 14% (115 of 828) were within six nucleotides of two repeats, and 16% (134 of 828) were from expanded alleles. The repeat distribution from the expanded alleles shows two modes at approximately 110 and 870 repeats. Without prior estimates from the Southern blot (Fig. 5c), we likely would have estimated the primary populations of this individual’s repeats at 2, 110, and 870 repeats. Because of the Southern blot, however, we know the primary population of the individual’s expanded repeat is near 1000 repeats, though it is possible the C9orf72 repeat expansion runs artificially high by Southern Blot because of methylation or high GC content. The 97.5th and 99th percentiles of this distribution’s probability density function are approximately 964 and 1011 repeats, which closely resemble estimates by Southern blot (Fig. 5c)