Clinical Spectrum and Science Behind the Hamartomatous Polyposis Syndromes.

The hamartomatous polyposis syndromes are a set of clinically distinct disorders characterized by the occurrence of hamartomatous polyps in the gastrointestinal tract. These syndromes include juvenile polyposis syndrome, Peutz-Jeghers syndrome, and PTEN hamartoma tumor syndrome. Although each of the syndromes has distinct phenotypes, the hamartomatous polyps can be challenging to differentiate histologically. Additionally, each of these syndromes is associated with increased lifetime risks of gene-specific and organ-specific cancers, including those outside of the gastrointestinal tract. Germline pathogenic variants can be identified in a subset of individuals with these syndromes, which facilitates molecular diagnosis and subsequent gene-enabled management in the setting of genetic counseling. Although the malignant potential of hamartomatous polyps remains elusive, timely recognition of these syndromes is important and enables presymptomatic cancer surveillance and management before symptom exacerbation. Presently, there are no standard agents to prevent the development of polyps and cancers in the hamartomatous polyposis syndromes.

Gentle Giant? Giant Gastric Solitary Peutz-Jeghers Polyp.

Solitary hamartomatous polyps with identical pathological features of the typical hamartomas of the Peutz-Jegher syndrome are extremely rare. These solitary lesions lack the associated intestinal polyposis, classic mucocutaneous pigmentation, and family history typifying the Peutz-Jegher syndrome. We describe the case of a 31-year-old woman with a giant solitary gastric hamartoma endoscopically diagnosed and laparoscopically resected.

When synchronous mucinous metaplasia and neoplasia of the female genital tract and peutz-jeghers syndrome meet: a case report and literature reviews.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is characterized by the presence of hamartomatous polyps in the gastrointestinal tract and mucocutaneous pigmentation on the lips, oral mucosa, nose, fingers, and toes. Synchronous mucinous metaplasia and neoplasia of the female genital tract (SMMN-FGT) refers to the occurrence of multifocal mucinous lesions in at least two sites, including the cervix, uterus, fallopian tubes, and ovaries, in the female genital tract. SMMN-FGT and PJS are rare diseases with a very low incidence, especially when occurring simultaneously. CASE PRESENTATION: We report a case in which a woman with a large mass on the left ovary underwent a gynecological surgery and was diagnosed with cervical gastric-type adenocarcinoma and mucinous lesions in the endometrium, bilateral fallopian tubes, and ovary, i.e., SMMN-FGT, by postoperative paraffin pathology. The patient sought medical attention for abdominal distension and enlargement. A gynecological ultrasound revealed a multilocular cystic mass in the pelvis, while serum tumor markers were within normal limits, with mildly elevated carbohydrate antigen 199 and carbohydrate antigen 125 levels. Cervical thin-prep cytology test result was negative. The patient had a family history of PJS with black spots on her skin and mucous membranes since the age of 8 years. She underwent multiple partial small bowel resections and gastrointestinal polypectomy owing to intestinal obstruction and intussusception. She underwent left adnexectomy, hysterectomy, right salpingectomy, greater omental resection, appendectomy and right ovary biopsy, and received six courses of adjuvant chemotherapy with Lopressor plus Carboplatin. Genetic testing revealed a heterozygous serine threonine kinase 11 germline mutation and there were no signs of recurrence during the 18-month follow-up period after treatment. CONCLUSIONS: This is a rare case in which PJS was complicated by SMMN-FGT. Owing to its extreme rarity, there are no guidelines, but reported cases appear to indicate a poor prognosis. We retrospectively reviewed all cases of collisions between PJS and SMMN-FGT and explored the clinical features, pathological characteristics, diagnosis, treatment methods, and prognosis when the two diseases coexisted. The aim is to deepen the clinicians' understanding of this disease for early detection, diagnosis and treatment.

Diagnosis and Management of Cancer Risk in the Gastrointestinal Hamartomatous Polyposis Syndromes: Recommendations From the US Multi-Society Task Force on Colorectal Cancer.

The gastrointestinal hamartomatous polyposis syndromes are rare, autosomal dominant disorders associated with an increased risk of benign and malignant intestinal and extraintestinal tumors. They include Peutz-Jeghers syndrome, juvenile polyposis syndrome, the PTEN hamartoma tumor syndrome (including Cowden's syndrome and Bannayan-Riley-Ruvalcaba syndrome), and hereditary mixed polyposis syndrome. Diagnoses are based on clinical criteria and, in some cases, confirmed by demonstrating the presence of a germline pathogenic variant. The best understood hamartomatous polyposis syndrome is Peutz-Jeghers syndrome, caused by germline pathogenic variants in the STK11 gene. The management is focused on prevention of bleeding and mechanical obstruction of the small bowel by polyps and surveillance of organs at increased risk for cancer. Juvenile polyposis syndrome is caused by a germline pathogenic variant in either the SMAD4 or BMPR1A genes, with differing clinical courses. Patients with SMAD4 pathogenic variants may have massive gastric polyposis, which can result in gastrointestinal bleeding and/or protein-losing gastropathy. Patients with SMAD4 mutations usually have the simultaneous occurrence of hereditary hemorrhagic telangiectasia (juvenile polyposis syndrome-hereditary hemorrhagic telangiectasia overlap syndrome) that can result in epistaxis, gastrointestinal bleeding from mucocutaneous telangiectasias, and arteriovenous malformations. Germline pathogenic variants in the PTEN gene cause overlapping clinical phenotypes (known as the PTEN hamartoma tumor syndromes), including Cowden's syndrome and related disorders that are associated with an increased risk of gastrointestinal and colonic polyposis, colon cancer, and other extraintestinal manifestations and cancers. Due to the relative rarity of the hamartomatous polyposis syndromes, recommendations for management are based on few studies. This U.S Multi-Society Task Force on Colorectal Cancer consensus statement summarizes the clinical features, assesses the current literature, and provides guidance for diagnosis, assessment, and management of patients with the hamartomatous polyposis syndromes, with a focus on endoscopic management.

Survival, surveillance, and genetics in patients with Peutz-Jeghers syndrome: A nationwide study.

Peutz-Jeghers syndrome (PJS) is an autosomal dominant hereditary polyposis syndrome causing increased morbidity and mortality due to complications of polyposis and the development of cancer. STK11 is the only gene known to be associated with PJS, although in 10%-15% of patients fulfilling the diagnostic criteria no pathogenic variant (PV) is identified. The primary aim of this study was to identify the genetic etiology in all known PJS patients in Denmark and to estimate the risk of cancer, effect of surveillance and overall survival. We identified 56 patients (2-83 years old) with PJS. The detection rate of PVs was 96%, including three cases of mosaicism (6%). In two patients a variant was not detected. At the age of 40 years, the probabilities of cancer and death were 21% and 16%, respectively; at the age of 70 years these probabilities were 71% and 69%. Most cases of cancer (92%) were identified between the scheduled examinations in the surveillance program. These observations emphasize that PJS should be regarded as a general cancer predisposition syndrome, where improvement of clinical care is needed.

Preimplantation genetic testing in two Danish couples affected by Peutz-Jeghers syndrome.

BACKGROUND: Guidelines from the European Hereditary Tumor Group as well as The Danish National Guidelines for Peutz-Jeghers Syndrome (PJS) state that both prenatal diagnosis and preimplantation genetic testing for monogenic disorders (PGT-M) should be offered to patients with PJS. However, only a few cases resulting in viable pregnancies have been published. OBJECTIVE: We present two cases of PJS patients going through PGT-M for PJS. We highlight the awareness of this possibility and discuss the technical and ethical challenges of performing PGT-M for PJS. METHODS AND RESULTS: Case 1: A 36-year-old male with PJS and his partner were referred for genetic counseling. The patient carried a pathogenic de novo variant in STK11. After a terminated pregnancy of a fetus carrying the same pathogenic variant, microsatellite polymorphic marker analysis was established, and the patient was offered PGT-M. The female partner of the patient gave birth to a healthy boy after five years of fertility treatment. Case 2: A 35-year-old female with PJS and her partner were referred for genetic counseling. She carried an inherited pathogenic STK11 variant. The couple was offered PGT-M. Genetic testing of the embryos was performed using microsatellite polymorphic markers. After two rounds of oocyte extraction a blastocyst predicted not to be affected by PJS was identified. The blastocyst was transferred; however, this did not result in a viable pregnancy. CONCLUSIONS: PGT-M can be offered to patients with PJS. The process may be long and filled with ethical dilemmas requiring patients to be motivated and persistent.

Clinical Guidelines for Diagnosis and Management of Peutz-Jeghers Syndrome in Children and Adults.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare disease characterized by the presence of hamartomatous polyposis throughout the gastrointestinal tract, except for the esophagus, along with characteristic mucocutaneous pigmentation. It is caused by germline pathogenic variants of the STK11 gene, which exhibit an autosomal dominant mode of inheritance. Some patients with PJS develop gastrointestinal lesions in childhood and require continuous medical care until adulthood and sometimes have serious complications that significantly reduce their quality of life. Hamartomatous polyps in the small bowel may cause bleeding, intestinal obstruction, and intussusception. Novel diagnostic and therapeutic endoscopic procedures such as small-bowel capsule endoscopy and balloon-assisted enteroscopy have been developed in recent years. SUMMARY: Under these circumstances, there is growing concern about the management of PJS in Japan, and there are no practice guidelines available. To address this situation, the guideline committee was organized by the Research Group on Rare and Intractable Diseases granted by the Ministry of Health, Labour and Welfare with specialists from multiple academic societies. The present clinical guidelines explain the principles in the diagnosis and management of PJS together with four clinical questions and corresponding recommendations based on a careful review of the evidence and involved incorporating the concept of the Grading of Recommendations Assessment, Development and Evaluation system. KEY MESSAGES: Herein, we present the English version of the clinical practice guidelines of PJS to promote seamless implementation of accurate diagnosis and appropriate management of pediatric, adolescent, and adult patients with PJS.

Gastric-type mucinous adenocarcinoma of the cervix in a woman with Peutz-Jeghers syndrome: a case report.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant disorder characterized by a predisposition to the development of multiple neoplasms. Gastric-type mucinous adenocarcinoma (GAS), a new variant of carcinoma of the cervix according to 2014 WHO classification, is less common compared with squamous cell carcinoma, is more aggressive and has a lower 5-year survival rate compared with the usual-type endocervical adenocarcinoma, and is also unrelated to human papillomavirus (HPV) infection. CASE SUMMARY: We herein present the case of a 32-year-old patient with PJS who was diagnosed with GAS of the cervix. The patient was not sexually active and had been diagnosed with PJS at 2 years of age. A tumor ∼6 cm was found on the cervix and was diagnosed as GAS of the cervix of clinical-stage IB3. The patient was treated with intra-arterial chemotherapy for one course, followed by radical surgery and then systematic chemotherapy. CONCLUSION: The present case highlights the need for more thorough cancer screening for patients with PJS, as this disorder is rare and is associated with a high risk of malignancies. Young patients with PJS, including those who are not sexually active, who present with watery vaginal discharge or bleeding should be screened for cervical carcinoma, even if the cytological results or HPV tests are negative.

[Management of the Peutz-Jeghers Syndrome]. / Management des Peutz-Jeghers-Syndroms.

The current evidence to guide management of Peutz-Jeghers Syndrome (PJS) is sparse. Here we summarise the European guidelines that were published in 2021 by the EHTG (European Hereditary Tumour Group), extended with new evidence on some aspects of clinical management that have been generated since then. EHTG with this revised guideline has updated and extended their own previous expert opinion guideline from 2010. For this purpose, all published literature was systematically screened and the level of evidence determined by using the GRADE methodology (Grading of Recommendations Assessment. Development and Evaluation). This was followed by a Delphi process and the consensus for a statement was achieved if the voting committee reached ≥ 80% approval.The only other more recently published guidelines encountered only addressed the clinical management of gastrointestinal and pancreatic manifestations of PJS. These recommendations were reviewed and adopted, since no further relevant literature was identified in the systematic literature search. However, additional questions were identified and formulated into recommendations after following the described process. It may be stated that 10 years after the predecessor guideline, new evidence has been sparse. As with all rare diseases, a call for more collaborative studies must here be made in order to improve patient management by addressing open clinical questions and generating collaborative evidence with increased case numbers, both nationally and internationally. With the limited published evidence, these European guidelines are the most current reference for management of PJS patients.

[The course and clinical manifestations of Peutz-Jeghers syndrome in the Russian population].

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare hereditary syndrome characterized by the growth of hamartomatous polyps in the gastrointestinal tract, perioral pigmentation and an increased risk of malignant neoplasms. The syndrome is caused by a pathogenic variant in the STK11 gene. AIM: To assess the clinical picture and treatment of Russian patients with PJS. MATERIALS AND METHODS: A retrospective analysis of 30 patients from 25 families with an established diagnosis of PJS who were in the Ryzikh State Scientific Center for Coloproctology from 2011 to 2021 was carried out. All patients underwent instrumental examination, including esophagogastroduodenoscopy, colonoscopy, X-ray examination of the small intestine/CT-enterography, in the absence of invaginates - video capsule endoscopy, as well as molecular genetic examination for the presence of pathogenic variants in the STK11 gene. All removed polyps were subjected to the histological examination. RESULTS: The analysis of the clinical picture allowed us to establish the following data: the first complaints in patients were noted in childhood and adolescence, while the median age was 11 [7; 19] (0.5-24) years; pathogenic variants in the STK11 gene were identified in 26 (87%) cases, among which 10 were described for the first time; during the initial examination, polyps in the small intestine were detected in all 30 (100%) patients, in the stomach - in 23/30 (77%) patients, and in the colon - in 21/30 (70%); with an age, an increase in the number of polyps in all parts of the gastrointestinal tract was noted; before the diagnosis operations were performed urgently for intestinal obstruction; after the diagnosis of PJS, when polyps were detected in the gastrointestinal tract, endoscopic polypectomies were performed; if endoscopic removal of hamartomatous polyps was impossible, patients were operated as planned; malignant diseases of the predominantly reproductive system were detected in 8/30 (27%) patients. The median age of cancer detection was 52 [31; 52] (17-59) years. CONCLUSION: Russian patients with PJS have population-specific features in the clinical picture of the course of the disease, which dictates the need to develop their own recommendations for monitoring and treatment of such patients.

Diagnosis and Management of Cancer Risk in the Gastrointestinal Hamartomatous Polyposis Syndromes: Recommendations From the US Multi-Society Task Force on Colorectal Cancer.

The gastrointestinal hamartomatous polyposis syndromes are rare, autosomal dominant disorders associated with an increased risk of benign and malignant intestinal and extraintestinal tumors. They include Peutz-Jeghers syndrome, juvenile polyposis syndrome, the PTEN hamartoma tumor syndrome (including Cowden's syndrome and Bannayan-Riley-Ruvalcaba syndrome), and hereditary mixed polyposis syndrome. Diagnoses are based on clinical criteria and, in some cases, confirmed by demonstrating the presence of a germline pathogenic variant. The best understood hamartomatous polyposis syndrome is Peutz-Jeghers syndrome, caused by germline pathogenic variants in the STK11 gene. The management is focused on prevention of bleeding and mechanical obstruction of the small bowel by polyps and surveillance of organs at increased risk for cancer. Juvenile polyposis syndrome is caused by a germline pathogenic variant in either the SMAD4 or BMPR1A genes, with differing clinical courses. Patients with SMAD4 pathogenic variants may have massive gastric polyposis, which can result in gastrointestinal bleeding and/or protein-losing gastropathy. Patients with SMAD4 mutations usually have the simultaneous occurrence of hereditary hemorrhagic telangiectasia (juvenile polyposis syndrome-hereditary hemorrhagic telangiectasia overlap syndrome) that can result in epistaxis, gastrointestinal bleeding from mucocutaneous telangiectasias, and arteriovenous malformations. Germline pathogenic variants in the PTEN gene cause overlapping clinical phenotypes (known as the PTEN hamartoma tumor syndromes), including Cowden's syndrome and related disorders that are associated with an increased risk of gastrointestinal and colonic polyposis, colon cancer, and other extraintestinal manifestations and cancers. Due to the relative rarity of the hamartomatous polyposis syndromes, recommendations for management are based on few studies. This US Multi-Society Task Force on Colorectal Cancer consensus statement summarizes the clinical features, assesses the current literature, and provides guidance for diagnosis, assessment, and management of patients with the hamartomatous polyposis syndromes, with a focus on endoscopic management.

Diagnosis and management of cancer risk in the gastrointestinal hamartomatous polyposis syndromes: recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer.

The gastrointestinal hamartomatous polyposis syndromes are rare, autosomal dominant disorders associated with an increased risk of benign and malignant intestinal and extraintestinal tumors. They include Peutz-Jeghers syndrome, juvenile polyposis syndrome, the PTEN hamartoma tumor syndrome (including Cowden's syndrome and Bannayan-Riley-Ruvalcaba syndrome), and hereditary mixed polyposis syndrome. Diagnoses are based on clinical criteria and, in some cases, confirmed by demonstrating the presence of a germline pathogenic variant. The best understood hamartomatous polyposis syndrome is Peutz-Jeghers syndrome, caused by germline pathogenic variants in the STK11 gene. The management is focused on prevention of bleeding and mechanical obstruction of the small bowel by polyps and surveillance of organs at increased risk for cancer. Juvenile polyposis syndrome is caused by a germline pathogenic variant in either the SMAD4 or BMPR1A genes, with differing clinical courses. Patients with SMAD4 pathogenic variants may have massive gastric polyposis, which can result in gastrointestinal bleeding and/or protein-losing gastropathy. Patients with SMAD4 mutations usually have the simultaneous occurrence of hereditary hemorrhagic telangiectasia (juvenile polyposis syndrome-hereditary hemorrhagic telangiectasia overlap syndrome) that can result in epistaxis, gastrointestinal bleeding from mucocutaneous telangiectasias, and arteriovenous malformations. Germline pathogenic variants in the PTEN gene cause overlapping clinical phenotypes (known as the PTEN hamartoma tumor syndromes), including Cowden's syndrome and related disorders that are associated with an increased risk of gastrointestinal and colonic polyposis, colon cancer, and other extraintestinal manifestations and cancers. Due to the relative rarity of the hamartomatous polyposis syndromes, recommendations for management are based on few studies. This U.S. Multi-Society Task Force on Colorectal Cancer consensus statement summarizes the clinical features, assesses the current literature, and provides guidance for diagnosis, assessment, and management of patients with the hamartomatous polyposis syndromes, with a focus on endoscopic management.

Laser therapy and light sources for labial lentigines in patients with Peutz-Jeghers syndrome.

Labial lentigines associated with Peutz-Jeghers syndrome are challenging and represent a cosmetic problem. Laser and intense-pulsed light sources (IPLS) can be used to treat these macules. However, there are few guidelines regarding the different types of protocols found in the literature. Thus, the purpose of this study was to review the pertinent literature on lasers and IPLS as therapy for labial lentigines in patients with Peutz-Jeghers syndrome. A detailed literature search was conducted in seven databases (Cochrane Library, Embase, Lilacs, PubMed, SciELO, Scopus and Web of Science) to November 2020. Data were extracted and analyzed from selected studies including study design, sample size, participants' skin color, age, and gender, parameters of the laser or IPLS used, interval and total sessions of laser application, results obtained, follow-up time and side effects. Thirteen out of 124 published studies met our eligibility criteria, covering 81 patients. Ten types of lasers and IPLS were used, and most of the sample (n = 57) was treated with Q-switch Alexandrite Laser (QSAL). The total number of sessions ranged from 1 to 12 and the interval between sessions ranged from 2 to 16 weeks. All studies have shown satisfactory results, with no further complications. The follow-up ranged from 2 to 97 months. Laser therapy and IPLS are effective in the treatment of lentigines associated with PJS. Although QSAL was used in 70.3% of the sample, different types of lasers showed comparable satisfactory results.

Endoscopic Therapy of Small Bowel Polyps by Single-Balloon Enteroscopy in Patients with Peutz-Jeghers Syndrome.

Background: Little is known about the efficacy and safety of single-balloon enteroscopy (SBE) in patients with Peutz-Jeghers syndrome (PJS). The aim of this study was to assess the efficacy and safety of SBE for the treatment of small bowel polyps in patients with PJS. Methods: We conducted a single-center observational study, which included all patients diagnosed with PJS who underwent SBE for polypectomy between January 2018 and March 2021. Complete treatment was defined as the absence of polyps ≥10 mm after SBE resection. The clinical records were retrospectively reviewed. Results: 102 patients (including 40 men and 62 women) with a mean age of 28.7 years (range 13-55 y) were enrolled in our study. The intubation depth via the oral approach of patients with a history of laparotomy was significantly shorter than that of the patients without a history of laparotomy ([241.6 ± 64.2] cm vs [280.9 ± 40.2] cm, P=0.008). The maximum size of the resected polyps via anus during the second hospitalization was significantly smaller than that during the first hospitalization ([2.25 ± 1.29] cm vs [4.26 ± 3.51] cm, P=0.032). For patients with total enteroscopy, the complete treatment rate was 98% (49/50). For patients without total enteroscopy, all polyps larger than 10 mm in the examined segment of small bowel were resected successfully. Complications occurred in 10 of 129 hospitalizations (delayed bleeding in 4, perforation in 3, and acute pancreatitis in 3). Conclusions: SBE is effective and safe for resection of small bowel polyps in patients with PJS.

Extremely high anti-Mullerian hormone levels detected during infertility workup revealing sex cord tumor with annular tubules and underlying Peutz-Jeghers syndrome: A case report.

We report an infertile, but otherwise asymptomatic woman, whose extremely high anti-Mullerian hormone (AMH) level detected during infertility investigation led to the diagnosis of sex cord tumor with annular tubules (SCTAT) which is a very rare sex cord-stromal tumor (SCST) and eventually revealed a previously undiagnosed hereditary cancer syndrome, Peutz-Jeghers syndrome (PJS). A 33-year-old woman attended Kocaeli University ART Clinic for infertility evaluation. Her AMH level was 319.63 ng/ml. Detection of bilateral ovarian cysts required surgical evaluation. The histopathological examination of ovaries revealed SCTAT. The strong association of SCTAT with PJS raised the suspicion of this syndrome. Whole STK11 gene sequencing confirmed PJS diagnosis. AMH has become a widely used tool in the evaluation of infertile women. Clinicians dealing with infertility should be familiar with the utility of AMH measurement besides being a marker of ovarian reserve. Detection of high AMH concentrations should raise the suspicion of an SCST.

Sex-Cord Tumor with Annular Tubules with Unusual Morphology in an Infant with Peutz-Jeghers Syndrome.

Background Peutz-Jeghers syndrome (PJS) is characterized by hamartomatous gastrointestinal polyposis, mucocutaneous pigmentation and cancer predisposition. The clinical features of PJS manifest in first two decades of life; however, neonatal presentation is uncommon. Case report: We present a five day old girl with PJS that presented with obstructive hamartomatous polyps in the sigmoid colon. At colostomy closure at six months, an incidental ovarian sex-cord tumor with annular tubules (SCTAT) was detected. It showed predominantly a solid pattern with limited tubule formation and was composed of lipid-rich cells. She had no hormonal symptoms. Conclusion: SCTAT can occur as young as six months of age in PJS, and may show histologic overlap with lipid-rich Sertoli cell tumors.

[A case of Peutz-Jeghers syndrome that developed triple cancers during the course].

At the time of colon polyp follow-up, a 46-year-old Japanese woman with a history of invagination, colon polyps, cervical cancer, and breast cancer was suspected of Peutz-Jeghers syndrome and referred. Multiple polyposes of the jejunum were discovered by capsule endoscopy and double-balloon endoscopy, and the resected specimen was diagnosed with hamartoma. During the follow-up, advanced pancreatic cancer-derived from IPMN developed. It is important to remember that multiple cancers can develop in Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome.

PURPOSE OF REVIEW: Peutz-Jeghers syndrome is a rare, autosomal dominant, hereditary polyposis syndrome defined by gastrointestinal hamartomas and mucocutaneous pigmentations, caused by a germline mutation in the serine/ threonine kinase 11 or liver kinase B1 (STK11/LKB1) genes. Hamartomatous polyps located throughout the gastrointestinal tract can be complicated by bleeding and small bowel intussusception, potentially leading to the need for emergency surgery. Individuals suffering from Peutz-Jeghers syndrome have an increased lifetime risk of various forms of cancer (gastrointestinal, pancreatic, lung, breast, uterine, ovarian and testicular). Surveillance should lead to the prevention of complications and thus a reduction in mortality and morbidity of patients. RECENT FINDINGS: A combined approach based on wireless capsule endoscopy, magnetic resonance enterography and device-assisted enteroscopy is effective in reduction of the polyp burden and thus decreasing the risk of bleeding and intussusception. Current guidelines for screening and surveillance are mostly based on expert opinion rather than evidence. SUMMARY: Peutz-Jeghers syndrome is an emerging disease that significantly affects the quality of life enjoyed by patients. Despite of all the progress in improved early diagnostics, options for advanced endoscopic therapy and elaborate surveillance, acute and chronic complications decrease the life expectancy of patients suffering from Peutz-Jeghers syndrome.

Paediatric polyposis syndromes: burden of disease and current concepts.

PURPOSE OF REVIEW: Polyposis syndromes are rare but significant entities that often present during childhood and adolescence. Polyposis syndromes should remain high on the differential diagnoses for any child presenting with rectal bleeding, protein-losing enteropathy or intussusception in the setting of multiple polyps in the gastrointestinal tract. There are three primary paediatric polyposis syndromes: Juvenile polyposis syndrome (JPS), Familial adenomatous polyposis (FAP) and Peutz-Jeghers syndrome (PJS). This review will cover recent guidelines for these conditions and advances in genetic testing. RECENT FINDINGS: The first set of paediatric guidelines were released in 2019 by the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) for FAP, JPS and PJS. Even with advances in genetic testing, a significant proportion of patients with polyposis syndromes have no identifiable genetic mutations. Recent research has shown that polyps behave differently in patients with and without disease-causing variants, emphasizing the role of genetic testing in the diagnosis and management of polyposis syndromes. SUMMARY: Polyposis syndromes in the paediatric population are growing due to increased recognition and advances in genetic testing. A timely diagnosis and surveillance of a paediatric polyposis syndrome are pivotal for the management of disease burden and early identification of cancers within the gastrointestinal tract and beyond. Paediatricians, paediatric gastroenterologists, paediatric oncologists and paediatric surgeons should be familiar with the presentation and comorbidities of polyposis syndromes in children and adolescents. Further research into genotype-phenotype correlations is needed to tailor the care for paediatric patients with polyposis syndromes.

Implications of Splicing Alterations in the Onset and Phenotypic Variability of a Family with Subclinical Manifestation of Peutz-Jeghers Syndrome: Bioinformatic and Molecular Evidence.

Peutz-Jeghers Syndrome (PJS) is an autosomal dominant pre-cancerous disorder caused in 80-90% of cases by germline mutations in the tumor suppressor gene STK11. We performed a genetic test of the STK11 gene in two Italian young sisters suspected of PJS, since they showed pathognomonic café au lait spots in absence of other symptoms and familiarity. Sequencing of all exons of STK11 gene and other 8 genes, suggested to be involved in hamartomatous syndromes, (PTEN, BMPR1A, SDHB, SDHD, SMAD4, AKT1, ENG, PIK3CA) led to the identification in both the probands of a novel germline silent mutation named c.597 G>A, hitting the last nucleotide of exon 4. Interestingly, genetic testing of the two probands' parents showed that their unaffected father was carrier of this mutation. Moreover, he carried a second intronic substitution named c.465-51 T>C (rs2075606) which was not inherited by his daughters. We also observed that all the family members carrying the c.597 G>A mutation presented an aberrant splice variant of STK11 mRNA lacking exon 4. Furthermore, in silico analysis of c.465-51 T>C substitution showed that it may activate an Enhancer Splicing Element. Finally, qRT-PCR analysis of STK11 expression levels showed a slight downregulation of the wild type allele in the father and a 2-fold downregulation in the probands compared to the unaffected mother. Our results have led the hypothesis that the c.465-51 T>C intronic variant, which segregates with the wild type allele, could increase the splicing effectiveness of STK11 wild-type allele and compensate the side effect of the c.597 G>A splicing mutation, being responsible for the phenotypic variability observed within this family. This finding highlight the importance of RNA analysis in genetic testing, remarking that silent DNA variant can often be splicing variant involved in disease onset and progression. The identification of these variants has a crucial role to ensure an appropriate follow-up and cancer prevention in at-risk individuals.