A shared ancestral haplotype in patients with pathogenic RFC1
motifs. Graphical representation of the haplotypes associated with AAGGG,
ACAGG and novel pathogenic repeat motifs identified in this study. For each single
nucleotide polymorphism, the reference allele is represented in blue, while the
alternative allele is represented in yellow. The repeat expansion locus is marked with
a red line (R). There is a shared region (B–C, -rs2066782-rs6851075,
chr4:39302305–39366034, hg38) of 66 kb for all novel configurations. A larger region
of 207 kb (A–C, rs148316325- rs6851075, chr4:39158847–39366034, hg38), which is
flanked by two recombination hotspots (arrows), is also shared among all but one
allele for Case III-1, suggesting a recombination event at B (rs2066782) in this
family. The shared haplotype lies in a region of low recombination rate (HapMap data)
and is delimited by small peaks at A and C. A smaller increase in the recombination
rate is also visible at B. hom = homozygous.