Case studies in the diagnosis and management of Peutz-Jeghers syndrome

Hereditary Cancer Syndromes-A Primer on Diagnosis and Management, Part 2: Gastrointestinal Cancer Syndromes

Hereditary causes due to mutations and defects in certain genes account for roughly 5% to 10% of all colorectal cancers. These inherited syndromes have been associated with a 60% to 100% lifetime risk for development of colorectal cancer, depending on the genetic syndrome, and many also carry an increased risk for multiple extracolonic malignancies. In this second part of a review series on hereditary cancer syndromes, the focus will be to provide guidance on the features and management of the most commonly encountered hereditary colorectal cancers and polyposis conditions including Lynch syndrome, familial adenomatous polyposis, MUTYH-associated polyposis, and hamartomatous polyposis.

Acute intussusception and polyp with malignant transformation in Peutz-Jeghers syndrome: A case report

Intussusception is one of the most frequent complications of Peutz-Jeghers syndrome, and has been well described in previous studies. More attention has been paid to malignancy, which is another complication of Peutz-Jeghers syndrome and which leads to increased mortality. Few cases of intussusception combined with malignant polyps in Peutz-Jeghers syndrome have been reported to date. In the present study, we report a case of intussusception and malignant polyps occurring in various parts of the small intestine in a 43-year-old male. In addition to repair of the intussusception and partial resection of the small intestine with malignant polyps, we also simultaneously performed polypectomy of as many polyps as possible without resection of the small intestine. Our aim is to make clinicians aware of intussusception and malignant polyps coexisting in Peutz-Jeghers syndrome when performing emergency surgery. Prophylaxis and polypectomy of the entire small bowel is an effective way to reduce the frequency of laparotomies in patients with this disease.

Clinical characteristics and STK11 gene mutations in Chinese children with Peutz-Jeghers syndrome

Background

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant inherited disease characterized by gastrointestinal hamartomatous polyps and mucocutaneous melanin spots. Germline mutation of the serine/threonine kinase 11 (STK11) gene are responsible for PJS. In this study, we investigated the clinical characteristics and molecular basis of the disease in Chinese children with PJS.

Methods

Thirteen children diagnosed with PJS in our hospital were enrolled in this study from 2011 to 2015, and their clinical data on polyp characteristics, intussusceptions events, family histories, etc. were described. Genomic DNA was extracted from whole-blood samples from each subject, and the entire coding sequence of the STK11 gene was amplified by polymerase chain reaction and analyzed by direct sequencing.

Results

The median age at the onset of symptoms was 2 years and 4 months. To date, these children have undergone 40 endoscopy screenings, 17 laparotomies and 9 intussusceptions. Polyps were found in the stomach, duodenum, small bowel, colon and rectum, with large polyps found in 7 children. Mutations were found in eleven children, including seven novel mutations (c.481het_dupA, c.943_944het_delCCinsG, c.397het_delG, c.862 + 1G > G/A, c.348_349het_delGT, and c.803_804het_delGGinsC and c.121_139de l19insTT) and four previously reported mutations (c.658C > C/T, c.890G > G/A, c.1062 C > C/G, and c.290 + 1G > G/A). One PJS patient did not have any STK11 mutations.

Conclusions

The polyps caused significant clinical consequences in children with PJS, and mutations of the STK11 gene are generally the cause of PJS in Chinese children. This study expands the spectrum of known STK11 gene mutations.

Peutz-Jeghers syndrome with germline mutation of STK11

Peutz-Jeghers syndrome (PJS), also known as periorificial lentiginosis, is a rare autosomal dominant inherited disease with an incidence of 1/200,000 live-borns. Mutations in the serine-threonine kinase 11 (STK11) gene are considered the major cause of PJS. The most frequent complication at young age is recurrent intussusception due to multiple hamartomatous polyps, primarily in the small intestine. Although extremely rare, the small bowel should be fully examined to be certain additional intussusceptions are not present. Herein, we report on a case of PJS with germline mutation of STK11 in a 12-year-old young girl who presented as a rare case of two small intestinal intussusceptions and review the literature.

Analysis of STK11 gene variant in five Chinese patients with Peutz-Jeghers syndrome

BACKGROUND

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant inherited disorder characterized by gastrointestinal hamartomatous polyps and mucocutaneous pigmentation. Germline mutation of a serine/threonine kinase 11(STK11) gene has been identified as a cause of PJS. In this study, we investigated the molecular basis of five Chinese PJS patients.

METHODS

Blood samples were collected from five unrelated Chinese PJS patients and their parents. The entire coding region of the STK11 gene was amplified by polymerase chain reaction and analyzed by direct sequencing.

RESULTS

Three different frameshift mutations (c.519insTGTG, c.792_793insT, and c.334_335insC), all of which would cause truncation of the gene product, were found in three patients. One missense mutation (p.Ser307Thr) and one 3bp deletion mutation (c.228-230del CGT) were identified in the remaining two patients. All of the five investigated patients carried de novo mutations.

CONCLUSIONS

The results support that mutation of the LKB1 gene is a cause of PJS, and expand the spectrum of the STK11 gene mutations.

Cancer problem in Peutz-Jeghers syndrome

Peutz–Jeghers syndrome is a rare autosomal dominantly inherited condition, characterized by the presence of hamartomatous gastrointestinal polyps and mucocutaneous pigmentation. Patients with this syndrome can be associated with other neoplasms such as ovarian neoplasms known as sex-cord tumor with annular tubules that are associated in one third of the cases with this syndrome and other types of malignancies. We report a 42-year-old woman with a history of Peutz–Jeghers Syndrome and bilateral breast cancer that presented with abnormal uterine bleeding. Total abdominal hysterectomy with bilateral salpino-oophorectomy was done and an ovarian sex cord tumor with annular tubules was incidentally diagnosed. By reviewing literatures and in agreement with previous studies we suggest routine screening for malignancies in patients with Peutz–Jeghers syndrome.