Figure 1.

Structures of ring chromosomes

(A) Nearly complete r(17) (NA10284).

(B) r(17) with terminal p-arm deletion and breakpoint insertion of duplicated sequence from 11q12.3 (NA06047).

(C) r(1) with terminal deletions as well as interstitial inversions and dispersed duplications.

(D) r(13) with terminal q-arm deletions and breakpoint in the acrocentric p-arm.

(E) r(14) with terminal q-arm deletion and breakpoint in the acrocentric p-arm.

(F) r(15) with terminal and interstitial q-arm deletion and loss of most of the acrocentric p-arm.

(G) r(21) with terminal q-arm deletion, inversion, and interstitial duplication.

Left in each panel, derivative structure of the ring chromosome, with segment labels corresponding to the reference chromosome on the right. In (G), the gray connector between copies of segment 1 indicates uncertainty about their fusion breakpoints. Right in each panel, loess-smoothed estimated copy number of the corresponding reference chromosome. Below, segments relevant to each rearrangement are labeled. Red, deleted segment; blue, duplicated segment; cyan, retained acrocentric p-arm segment with unreliable copy number estimates due to repeat content; gray, segment with no change in copy number. Centromeres are shown as black ovals. Magnifying glasses depict segments, as zoomed-in views, that are too narrow to be visible in the main linear ideograms.