Here we reported a particular case of MUTYH-associated polyposis (MAP) that had only one rare heterozygous variant, but some particular clinical manifestations contributed to occur in this male patient by only one defective MUTYH allele were worth of further investigation. We reported a case of MAP. It is about a 33-year-old man with chief complaints of hematochezia who had multiple polyps that were found in his colon via colonoscopy. He followed his doctor\'s advice and performed a genetic analysis examination. Germline test was positive for a major heterozygous variant: chr1:45800165 on the MUTYH gene. MUTYH gene sequence analysis confirmed the following heterozygous variant: c.55CT (p.R19X) in exon 2 (ClinVar NM_001128425). Unfortunately, his mother and daughter have the ILK variant according to genetic analysis. However, this variant at the site was not detected in his father. Various types of polyps were found on repeated colonoscopy, which tended to become latent cancerous in the future. This case indicated that awareness of the risk of carcinogenesis of polyps in carriers of monoallelic variants might accordingly increase, and our understanding of the type of genetically related disease will be enhanced by us.

OBJECTIVE: The current procedure for identifying hereditary colorectal cancer (HCRC) is time consuming in clinical practice. This study aimed to develop a time-saving approach to diagnosing HCRC.
METHODS: A total of 100 suspected HCRC patients were prospectively enrolled (cohort 1) and 116 colorectal cancer patients with DNA mismatch repair-deficient were retrospectively included (cohort 2). Next-generation sequencing (NGS) tests were performed on tumors and matched white blood cells (WBCs) or normal tissues. Using the conventional method upon WBC/normal tissue-based NGS data as a reference, the performance of the ColonCore method using tumor-only-based NGS data in predicting germline variants was explored in cohort 1 and validated in cohort 2.
RESULTS: In cohort 1, the ColonCore method diagnosed 17 Lynch syndrome (LS) and 14 familial adenomatous polyposis (FAP); and by the conventional method, the cases were 16 and 10, respectively. The ColonCore method showed sensitivities of 100% in diagnosing LS (positive predictive value [PPV] 94.1%) and FAP (PPV 71.4%). Moreover, two of seven patients with multiple adenomas/polyps who did not meet existing clinical criteria for HCRC were predicted to harbor germline variants in APC and MUTYH. Additionally, the sensitivity of the ColonCore method in identifying LS patients from cohort 2 reached 85.7% with a PPV of 85.7%.
CONCLUSIONS: The ColonCore method might be an acceptable tool for predicting germline variants associated with HCRC. Our work indicates the essentiality of NGS tests in CRC patients for precision diagnosis and treatment.

OBJECTIVE: To assess whether fecal pH might be an indicator of pouchitis during the postoperative period in hereditary colorectal cancer (CRC) patients who have undergone ileal pouch anal anastomosis (IPAA).
METHODS: Five consecutive daily pH values of stool samples from 31 familial adenomatous polyposis (FAP) patients and 32 metachronous Lynch syndrome patients who underwent IPAA procedures were reviewed. Patients with pouchitis (pouchitis group, n = 22) were compared with patients without pouchitis (nonpouchitis group, n = 41). A receiver operating characteristic (ROC) analysis was performed to determine the indicative potential of fecal pH for pouchitis. A Mantel-Cox test was also performed to evaluate the survival status of patients with or without pouchitis.
RESULTS: Pouchitis was noted in 22 (34.9%) of 63 patients after IPAA. The significance of each daily average fecal pH value and the 5-day overall average fecal pH value was compared between the two groups (P < .01). A cutoff fecal pH value of 7.46 was determined by the ROC analysis for assessing the risk of pouchitis. No significant difference in 5-year overall survival was observed between the two groups.
CONCLUSIONS: A lower fecal pH value in patients with hereditary CRC after IPAA might be a new indicator of pouchitis.

Lynch syndrome (LS), which is the most common hereditary colorectal cancer, accounts for about 3% of all colorectal cancers. However, due to its various clinical manifestations, it is difficult to be diagnosed. The diagnosis of LS requires comprehensive application of various screening criteria (such as the Amsterdam criteria, Bethesda criteria), predictive models, risk factors, immunohistochemistry test of mismatch repair (MMR) protein, microsatellite instability (MSI) detection, MLH1 methylation detection, BRAF gene mutation detection, germline gene mutation detection, and so on. LS can be diagnosed only after the identification of pathogenic germline mutation of MMR gene. The first-degree and second-degree relatives of LS patients are recommended to be tested for the identified mutant gene. For LS patients and gene mutation carriers, LS associated cancer can be detected early or even prevented by monitoring and preventive surgery. Reproductive techniques can be used to prevent this disease from being passed down to the next generation.
林奇综合征约占所有结直肠癌的3%，是最常见的遗传性结直肠癌，但是由于其临床表现多样，诊断困难。其筛查需要综合应用阿姆斯特丹（Amsterdam）、贝塞斯达（Bethesda）等各种筛查标准、预测模型、警示表现、免疫组织化学检测错配修复缺陷（dMMR）、微卫星不稳定性（MSI）、MLH1甲基化、BRAF基因突变和胚系基因突变检测等各种方法。只有找到了错配修复基因的致病性胚系突变后，才能确诊为林奇综合征。建议患者的一级亲属和二级亲属均检测该突变基因。通过对患者和基因突变携带者进行随访监测和预防性手术，可以早期发现、甚至预防癌症，还可以通过生殖医学的手段，阻止该疾病遗传给下一代。.

Colorectal cancer (CRC) is a common malignant tumor of the digestive system worldwide, associated with hereditary genetic features. CRC with a Mendelian genetic predisposition accounts for approximately 5-10% of total CRC cases, mainly caused by a single germline mutation of a CRC susceptibility gene. The main subtypes of hereditary CRC are hereditary non-polyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP). With the rapid development of genetic testing methods, especially next-generation sequencing technology, multiple genes have now been confirmed to be pathogenic, including DNA repair or DNA mismatch repair genes such as APC, MLH1, and MSH2. Since familial CRC patients have poor clinical outcomes, timely clinical diagnosis and mutation screening of susceptibility genes will aid clinicians in establishing appropriate risk assessment and treatment interventions at a personal level. Here, we systematically summarize the susceptibility genes identified to date and the potential pathogenic mechanism of HNPCC and FAP development. Moreover, clinical recommendations for susceptibility gene screening, diagnosis, and treatment of HNPCC and FAP are discussed.

OBJECTIVE: To investigate the impacts of perioperative blood transfusion on the immune function and prognosis in colorectal cancer (CC) patients.
METHODS: A retrospective analysis was conducted in 1404 CC patients, including 1223 sporadic colorectal cancer (SCC) patients and 181 hereditary colorectal cancer (HCC) patients. Among them, 701 SCC and 102 HCC patients received perioperative blood transfusion. The amount of T lymphocyte subsets and natural killer (NK) cells was measured. All patients received a 10-year follow-up and relapse, metastasis and curative conditions were recorded.
RESULTS: In SCC group, mortality, local recurrence and distant metastasis rate of transfused patients were significantly higher than non-transfused patients (all P <0.05). In HCC group, mortality was apparently higher in transfused patients than non-transfused patients (P = 0.002). SCC patients transfused with ≥3 U of blood had significantly higher mortality than patients transfused with <3 U (P = 0.006). The amount of T lymphocyte subsets and NK cells showed statistical differences before and after perioperative blood transfusion in SCC and HCC patients (all P <0.05). Also, there existed statistical differences in CD4+/CD8+ ratio among SCC patients before and after the perioperative blood transfusion (P <0.05). CC patients who received perioperative blood transfusion had markedly lower 10-year survival rates as compared with those who did not receive (both P <0.05). SCC patients transfused with ≥3 U of blood had remarkably lower survival rates compared with SCC patients transfused with <3 U (P = 0.002).
CONCLUSIONS: Perioperative blood transfusion could impact immune function, increased postoperative mortality, local recurrence rate and distant metastasis rate in CC patients; and survival rate of CC patients is negatively related to blood transfusion volume.