Peutz-Jeghers Syndrome (PJS) is characterized by intestinal polyposis, mucocutaneous pigmentation and an increased risk of developing multi-organ cancer, mainly in the gastrointestinal tract. Germline mutations of the STK11 gene are usually responsible for this syndrome. The aim of the present work is to report the case of a Uruguayan young patient with an atypical presentation of PJS. Extensive clinical data from the patient was obtained. Characteristic clinical diagnosis based on the presence of mucocutaneous pigmentation of the lips and oral mucosa and gastrointestinal hamartomatous polyps appeared several years later of the first gastrointestinal event (classified as “juveline polyp”) which deferred the molecular diagnosis. Complete sequencing of the STK11 gene was performed by NGS in the proband and his parents. The patient presented a novel large deletion spanning exon 5 to 10 of STK11 gene. This mutation was absent in both parents.
