STK11 and Peutz-Jeghers syndrome: Several heterozygous mutations in the STK11 gene, including frameshift and missense mutations, duplications, deletions, and splicing errors causing PJS, have been identified [10,11,12,13,14,15]; however, a few studies evaluated the genotype-phenotype correlation in PJS, producing discordant results [16,17,18,19].