遗传性非息肉病性结肠直肠癌 ( hereditary non-polypo-sis colorectal carcinoma,HNPCC)又称 L ynch综合征 ,为常染色体显性遗传性疾病 ,外显率约 5 0 % ,临床上约占大肠癌的 5 %～ 15 %。我们收集了 9个家系 40例严格符合 Amster-dam标准的 HNPCC患者 ,报告如下。1　临床资料 Hereditary non-polypoid sis colorectal carcinoma (HNPCC), also known as Lnnch syndrome, is an autosomal dominant genetic disease, about 50% penetrance, clinically about the large intestine Cancer 5% ~ 15%. We collected 40 pediatric HNPCC patients with 40 families that met Amster-dam criteria and are reported below. 1 clinical data