Supplemental Figure S2.

The repeat-primed (RP) profiles of the AmplideX-C9 assay and the sequences of the representative cases carrying the C9orf72 expansion with insertions/deletions (indels) downstream of the expansion region. The 22-bp region with frequent indels in the downstream region of the hexanucleotide repeat region, (GGGGCC)_n, is shown in the red boxed area in the top reference sample. G₄C₂ repeat sizes are indicated in each electropherogram. exp, expansion; exp^del, expansion with deletion.