Alu-Mediated Genomic Deletion of the Serine/Threonine Protein Kinase 11 (STK11) Gene in Peutz–Jeghers Syndrome

Molecular characterization of the STK11/LKB1 intragenic deletion. (A) Repetitive elements present in the genomic region from exons 1–4 of the STK11/LKB1 gene and a diagram (below) of the deletion are shown. The arrow indicates the novel genomic junction; 5′ BP and 3′ BP: 5′ and 3′ breakpoints. (B) Sequence analysis of the amplified product obtained from deleted allele. Boxed sequence corresponds to the twelve nucleotides repeated both at the 5′ and 3′ breakpoints sharing 100% of homology and representing the novel genomic connection produced by the deletion event. Bold arrows indicate the genomic region involved in the deletion and the genomic nucleotides position involved in the novel genomic junction, referred to GenBank sequence with accession number: NC_000019.9. (C) Sequence of Alu elements present at the 5′ and 3′ breakpoints (5′ BP, 3′ BP, of A); boxed nucleotides represent the core sequence of Alu elements.