Tandem duplication of PLAU in subjects with QPD and alignment of the junction sequence. The duplicated, approximately 78-kb region (yellow arrow) on chromosome 10 in QPD includes PLAU and all of its characterized regulatory elements (top diagram, not to scale) and C10orf55 (not shown) on the antisense strand to PLAU, a gene of unknown function. Alignment of the breakpoint junction between the copies (below) with the normal gene sequence indicates that the QPD duplication resulted from nonhomologous recombination.