High-Tech Diagnostic Methods and Enteroscopic Treatment of Children with Peutz-Jeghers Syndrome

Two missense STK11 gene variations impaired LKB1/adenosine monophosphate-activated protein kinase signaling in Peutz-Jeghers syndrome

BACKGROUND

Peutz-Jeghers syndrome (PJS) is a rare hereditary neoplastic disorder mainly associated with serine/threonine kinase 11 (STK11/LKB1) gene mutations. Preimplantation genetic testing can protect a patient's offspring from mutated genes; however, some variations in this gene have been interpreted as variants of uncertain significance (VUS), which complicate reproductive decision-making in genetic counseling.

AIM

To identify the pathogenicity of two missense variants and provide clinical guidance.

METHODS

Whole exome gene sequencing and Sanger sequencing were performed on the peripheral blood of patients with PJS treated at the Reproductive and Genetic Hospital of Citic-Xiangya. Software was employed to predict the protein structure, conservation, and pathogenicity of the two missense variation sites in patients with PJS. Additionally, plasmids were constructed and transfected into HeLa cells to observe cell growth. The differences in signal pathway expression between the variant group and the wild-type group were compared using western blot and immunohistochemistry. Statistical analysis was performed using one-way analysis of variance. P < 0.05 was considered statistically significant.

RESULTS

We identified two missense STK11 gene VUS [c.889A>G (p.Arg297Gly) and c.733C>T (p.Leu245Phe)] in 9 unrelated PJS families who were seeking reproductive assistance. The two missense VUS were located in the catalytic domain of serine/threonine kinase, which is a key structure of the liver kinase B1 (LKB1) protein. In vitro experiments showed that the phosphorylation levels of adenosine monophosphate-activated protein kinase (AMPK) at Thr172 and LKB1 at Ser428 were significantly higher in transfected variation-type cells than in wild-type cells. In addition, the two missense STK11 variants promoted the proliferation of HeLa cells. Subsequent immunohistochemical analysis showed that phosphorylated-AMPK (Thr172) expression was significantly lower in gastric, colonic, and uterine polyps from PJS patients with missense variations than in non-PJS patients. Our findings indicate that these two missense STK11 variants are likely pathogenic and inactivate the STK11 gene, causing it to lose its function of regulating downstream phosphorylated-AMPK (Thr172), which may lead to the development of PJS. The identification of the pathogenic mutations in these two clinically characterized PJS patients has been helpful in guiding them toward the most appropriate mode of pregnancy assistance.

CONCLUSION

These two missense variants can be interpreted as likely pathogenic variants that mediated the onset of PJS in the two patients. These findings not only offer insights for clinical decision-making, but also serve as a foundation for further research and reanalysis of missense VUS in rare diseases.

Cancer Risk of Peutz-Jeghers Syndrome and Treatment Experience: A Chinese Medical Center

Peutz-Jeghers syndrome (PJS), also known as hereditary mucocutaneous pigmented gastrointestinal polyposis, is a clinically rare autosomal dominant genetic disease, which falls into the category of hereditary colorectal cancer. There are ∼7,000 new cases of PJS in China every year, and 170,000 PJS patients may survive for a long time in society. PJS polyps are characterized by an early age of onset, difficult diagnosis and treatment, and easy recurrence. With repeated growth, polyps can lead to serious complications such as intestinal obstruction, intussusception, gastrointestinal bleeding, and cancerization, which cause serious clinical problems. Due to repeated hospitalization and endoscopic follow-up, PJS patients and their families suffer from great physical and mental pain and economic burden. With the in-depth understanding of PJS and the development and popularization of endoscopic techniques in the past decade, an integrated treatment modality based on endoscopy plus surgery has gradually become the preferred treatment in most hospitals, which greatly improves the quality of life of PJS patients. However, there is still a lack of effective drug prevention and cure means. In this paper, the current clinical treatment means for PJS polyps were summarized by literature review combined with the treatment experience of our medical center, with a focus on their clinical diagnosis, treatment, and cancer risk.

Paediatric gastrointestinal endoscopy in the Asian-Pacific region: Recent advances in diagnostic and therapeutic techniques

There has been a rapid expansion in the knowledge of paediatric gastroenterology over the recent decade, with a fast-growing repertoire of diagnostic techniques and management strategies for a wide spectrum of childhood gastrointestinal (GI) diseases. Paediatric GI endoscopy is a core competency every paediatric gastroenterologist should possess, and represents one of the most common procedures performed in children for both diagnostic and therapeutic purposes. Yet there remains a dearth of literature on the utility and outcomes of paediatric GI endoscopy in the Asia-Pacific region. Data on the diagnostic value of paediatric GI endoscopy would be an important aspect of discussion, with the emergence of inflammatory bowel disease (IBD) and eosinophilic GI disease as increasingly common endoscopic diagnoses. Time-based trends in paediatric GI endoscopy do point towards more IBD and gastroesophageal reflux disease-related complications being diagnosed, with a declining incidence of GI bleeding. However, the real-world diagnostic value of endoscopy in Asia must be contextualised to the region-specific prevalence of paediatric GI diseases. Helicobacter pylori infection, particularly that of multidrug-resistant strains, remains a highly prevalent problem in specific regions. Paediatric functional GI disorders still account for the majority of childhood GI complaints in most centres, hence the diagnostic yield of endoscopy should be critically evaluated in the absence of alarm symptoms. GI therapeutic endoscopy is also occasionally required for children with ingested foreign bodies, intestinal polyposis or oesophageal strictures requiring dilation. Endoscopic haemostasis is a potentially life-saving skill in cases of massive GI bleeding typically from varices or peptic ulcers. Advanced endoscopic techniques such as capsule endoscopy and balloon-assisted enteroscopy have found traction, particularly in East Asian centres, as invaluable diagnostic and therapeutic tools in the management of IBD, obscure GI bleeding and intestinal polyposis. State of the art endoscopic diagnostics and therapeutics, including the use of artificial intelligence-aided endoscopy algorithms, real-time confocal laser endomicroscopy and peroral endoscopic myotomy, are expected to gain more utility in paediatrics. As paediatric gastroenterology matures as a subspecialty in Asia, it is essential current paediatric endoscopists and future trainees adhere to minimum practice standards, and keep abreast of the evolving trends in the diagnostic and therapeutic value of endoscopy. This review discusses the available published literature on the utility of paediatric GI endoscopy in Asia Pacific, with the relevant clinical outcomes.

Small bowel endoscopy for children: Collaboration of capsule endoscopy and device-assisted enteroscopy

Capsule endoscopy (CE) and balloon-assisted enteroscopy (BAE) have become indispensable techniques for the diagnosis and management of small bowel disease in both adult and pediatric cases. However, relevant differences exist in the indications between these cohorts, with body weight and age having particular relevance in decisions for the latter. Both CE and BAE are designed for adult physique and they were not widely used among children. In addition, the types of small intestinal diseases differ between adults and children, and consequently, the indications also differ between them. This review focuses on the issues relevant to pediatric cases and describes the practical application of endoscopy in clinical practice. In conclusion, although there are age and weight restrictions, both CE and BAE are safe and useful devices for use in children, and their indications for use in children are likely to expand in the future.

Safety and efficacy of an enteroscopy-based approach in reducing the polyp burden in patients with Peutz-Jeghers syndrome: experience from a tertiary referral center

Background:

Patients with Peutz–Jeghers syndrome develop hamartomatous polyps in the small bowel, possibly causing anemia, intussusception, and obstruction. We aimed to evaluate the impact of an enteroscopy-based approach, including both device-assisted and intraoperative enteroscopy, on the reduction of the polyp burden in a cohort of adult Peutz–Jeghers syndrome patients.

Materials and methods:

A retrospective study was conducted at Azienda Ospedaliero-Universitaria Città della Salute e della Scienza in Turin, Italy. Consecutive Peutz–Jeghers syndrome patients eligible for device-assisted or intraoperative enteroscopy, between January 2003 and November 2019, were included. Enteroscopy technical issues and complications were recorded. At the time of index enteroscopy, the patients’ clinical records were retrospectively reviewed, and clinical data were recorded until November 2019.

Results:

Overall, 24 patients were included. Before inclusion, 16/24 patients (66.7%) underwent small bowel surgery for polyp-related complications, 13 of which (81.2%) in an emergent setting. Two patients had a history of small bowel neoplasms. During the timeframe, 47 device-assisted enteroscopies and 9 intraoperative enteroscopies were performed, and 247 small bowel polyps were endoscopically removed. The overall complication rate was 12.8% (8.5% for device-assisted enteroscopy, 22.2% for intraoperative enteroscopy). The median observation time was 108 months: in this timeframe, two patients developed small bowel polyp-related complications requiring emergent surgery. No patients developed small bowel cancer, but nine extra-gastrointestinal neoplasms were recorded.

Conclusion:

An enteroscopy-based approach appears to be well tolerated and effective in decreasing polyp-related complications in Peutz–Jeghers syndrome patients, thus reducing the need for emergent surgery. Although the prevention of small bowel polyp-related complications remains the main goal in these patients, the high incidence of extra-gastrointestinal neoplasms appears to be a rising issue.