A possible model for the pathogenesis of the deletion. (Ai) AluY repeats, highlighted in dark gray (5′) and light gray (3′) at the 5′ and 3′ deletion breakpoints line up while attached to the nuclear matrix, followed by a recombination event. This results (Aii) in the deletion of 8631 bp, including exons 4 and 5 from VWF. (B) An 85.2% (52 of 61) homology between the 5′ and 3′ AluY sequences 30 bp on either side of the deletion breakpoints (highlighted in dark gray).