A Clinical and Molecular Genetic Study in 11 Chinese Children With Peutz-Jeghers Syndrome

The Progress of Colorectal Polyposis Syndrome in Chinese Population

The pathogenesis, clinical phenotype, treatment strategy, and family management of hereditary tumor syndromes are different from those of sporadic tumors. Nearly a quarter of patients with colorectal cancer show significant familial aggregation and genetic predisposition, and 5 to 10% are associated with definite genetic factors. According to the clinical phenotype, it can be divided into nonpolyposis syndrome and polyposis syndrome. Among the polyposis syndrome patients with definite clinical symptoms, there are still some patients with unknown etiology (especially attenuated familial adenomatous polyposis), which is a difficult problem in clinical diagnosis and treatment. Therefore, for this rare disease, it is urgent to carry out multicenter studies, complete the gene variation spectrum, explore new pathogenic factors, and accumulate clinical experience. This article mainly introduces the research progress and related work of colorectal polyposis syndrome in China.

The role of double-balloon enteroscopy in reducing the maximum size of polyps in patients with Peutz-Jeghers syndrome: 12-year experience

OBJECTIVE

This study aimed to evaluate the role of double-balloon enteroscopy (DBE) in treating intestinal polyps in patients with Peutz-Jeghers syndrome (PJS).

METHODS

All patients diagnosed with PJS who underwent a polypectomy under DBE from October 2006 to December 2018 were enrolled. Their clinical records, including surgical history, the method of DBE insertion, the number of DBE procedures, and the maximum size and number of the resected polyps, were retrospectively reviewed.

RESULTS

Altogether 97 patients were enrolled. For both antegrade and retrograde DBE the maximum size of the resected polyps during the second hospitalization was significantly smaller than that during the first hospitalization (antegrade DBE: [2.13 ± 1.51] cm vs [3.63 ± 0.92] cm, P = 0.012; retrograde DBE: [1.20 ± 1.10] cm vs [2.95 ± 1.95] cm, P = 0.03), but was significantly larger than that during the third hospitalization (antegrade DBE: [2.13 ± 1.51] cm vs [0.88 ± 0.70] cm, P = 0.012; retrograde DBE: [1.20 ± 1.10] cm vs [0.46 ± 0.40] cm, P = 0.048). The interval between the second and third hospitalizations was significantly longer than that between the first and second hospitalizations ([899.00 ± 382.12] days vs [537.27 ± 326.28] days, P = 0.027). The success rate of total enteroscopy was 58.3% (28/48), which was not affected by a history of laparotomy (61.5% vs 52.4%, P = 0.528). The complication rate was 4.4%.

CONCLUSION

DBE is clinically safe and effective for the diagnosis and treatment of intestinal polyps in patients with PJS.

Clinical and Genetic Study of Children With Peutz-Jeghers Syndrome Identifies a High Frequency of STK11 De Novo Mutation

OBJECTIVES

The present study aims to identify the genotype-phenotype correlation in children with Peutz-Jeghers Syndrome (PJS) through the analysis of STK11 gene mutations in the context of clinical and pathological characteristics.

METHOD

In this observational cohort study, the clinical characteristics of 18 families diagnosed with pediatric PJS were collected. Genomic DNA from the peripheral blood of affected children and their family members was collected. The coding region of STK11 was amplified by PCR and screened for mutation by Sanger sequencing. The families that were negative for STK11 mutation were further assessed by multiplex ligation-dependent probe amplification (MLPA).

RESULT

Initial presentation in affected children was at 1.6 to 14.2 years and included anemia in 8 patients whereas 6 presented for screening by virtue of family history. All patients underwent endoscopy, colonoscopy, and polypectomy. Polyps were distributed throughout the gastrointestinal (GI) tract, including the small intestine, stomach, colon, and rectum.In the 18 pediatric PJS families, STK11 mutations were detected in 8 families by Sanger sequencing, and large deletions were detected in 3 by MLPA, respectively. Nine of the 11 STK11 mutations were de novo, 3 were novel (c.419T>C:p.L140P, c.314T>G:p.L105X), and (c.488_489insACGG p.L164fs).

CONCLUSIONS

Although the main clinical features of pediatric PJS were similar to those of PJS cases in adults, a high frequency of STK11 de novo mutations were encountered in our population of patients with PJS.

STK11 gene analysis reveals a significant number of splice mutations in Chinese PJS patients

BACKGROUND

The combination of direct sequencing and multiple ligation-dependent probe amplification (MLPA) has resulted in an 80% detection rate of serine/threonine kinase 11 (STK11) gene mutations in Peutz-Jeghers syndrome (PJS); however, this rate varies in different ethnicities.

AIMS

To test the efficacy of the combination in Chinese patients with PJS.

METHODS

PJS probands visiting our center during one year were enrolled. Sanger sequencing and MLPA were used to detect STK11 mutations. Associations between the occurrence of severe complications and risk factors were analyzed statistically.

RESULTS

We identified 47 PJS probands. Among them, 34 received an STK11 mutation test, revealing 23 point mutations and 2 exonic deletions. Nine of the mutations were splicing errors, reflecting a significantly higher proportion (p < 0.05). Laparotomy history existed for 33 of the probands, and seven families had a history of cancer. Statistical analysis revealed no associations between the occurrence of severe complications or cancers and risk factors.

CONCLUSION

The strategy achieved a high detection rate in Chinese people, validating its effectiveness. This cohort comprised a significantly higher proportion of splicing errors, reflecting the unique genetic characteristics Chinese people. No specific genotype-phenotype relationship was noted, while the wide usage of enteroscopy would benefit PJS surveillance.