Figure 1

A-B Title: Partial GTL karyotypes and ideograms of the two mosaic inv dup cases. 1A: Case 1 with karyotype 46,XY,inv dup del(4)(:p15.1->p16.3::p16.3::p16.3->qter).ish inv dup del(4)(GS-36p21-,WSCR++,GS-963K6+,wcp4+)/46,XY.ish del(4)(p16.3p16.3)(GS-36p21-). 1B: Case 2 with karyotype 46,XX,inv dup(10)(:p11->p15.3::p15.3->qter).ish inv dup dup(10)(NEBL1+,GATA3+,GS-306F7++,GATA3+,NEBL1+,GS137E24+,wcp10+)/46,XX.ish del(10)(p16.3p16.3)(GS-306F7-,GS137E24+. The GTL patterns for both cases suggest an inverted duplication. Note in both cases a prior interstitial region is redirected to a telomeric position on the tip of the p-arm. In the rearranged chromosomes, the new pter regions should, in theory, be stabilised with telomeric sequences either by telomere capture or by neotelomere formation.