Scheme of the two large deletions in SLC7A7 originated by the crossing over between two direct Alu repeats, found in LPI patient nos. 3 and 5. (a) Genomic scheme of the SLC7A7 gene and the 12 kb deletion (DelE4-E11) found in patient no. 3, with a breakpoint at 4294 bp upstream exon 4 and 1028 bp downstream exon 11 (c.500−4294_1908+1028del12136). Notice that the breakpoint could be generated in any of the nucleotides in the box, as this 20 nt sequence is the same in both the Alu repeats involved in this genomic rearrangement. The mutation nomenclature localizes the breakpoint at the 3′ end of the 20 nt sequence. (b) The 4.6 kb deletion (DelE6-E11) found in patient no. 5, had the breakpoint at 848 bp upstream of exon 6 and 718 bp downstream of exon 11 (c.771−848_1908+718del4647). In DelE4-E11, the breakpoint was at the 3′ end of AluY, whereas in DelE6-E11, the breakpoint was located at the first nucleotide of the AluY sequence.