Figure 4. Complex Rearrangements at the 4q35 Locus.

(A) Presence of a large deletion encompassing the proximal pink and blue probes in a patient (30-I1, Table) affected with FSHD, with deletion of a number of D4Z4 units. The size of the deletion is estimated of more than 42 kb. (B) This patient (31-I₁) carries a deletion of the proximal 4q35 region upstream of D4Z4 (>42 kb) together with a complex rearrangement of one 10q end. This rearrangement consists in the cis-duplication of 5 D4Z4 arrays of different sizes, all flanked by red probes (A-type allele) and separated by the gap present between the type A allele and the telomere. (C) This patient (27-I₁) carries a triplication of D4Z4 arrays of different sizes (39 RUs, 13 RUs, 5 RUs from the centromere to the telomere). The 2 additional D4Z4 arrays are flanked by A-type probes, and all repeated arrays are separated by a gap. (D) Patient 32-I₁ carries a cis-duplication of the blue probe encompassing the p13E11 probe (D4S104S1 marker), upstream of a short D4Z4 array (17 kb, 5 RUs). (E) Presence of a large duplication of the 4q35 region encompassing the proximal chromosome 4–specific region (red, pink, and blue probes) followed by a short D4Z4 array (9 RUs). This region is followed by a larger chromosome 4–specific region (red, pink, and blue probes) containing a 205 kb long D4Z4 array (62 RUs). Each D4Z4 array is followed by an A-type probe. (F) Presence of a large duplication of the 4q-specific region encompassing the proximal regions (red, pink, and blues probes), the D4Z4 array and the A-type probe. The 2 different D4Z4 arrays are of different sizes (135 kb, 41 RUs and 170 kb, 51 RUs) and above the threshold of 10 units. FSHD = facioscapulohumeral dystrophy.