A Novel Germline Mutation in Exon 10 of the SMAD4 Gene in a Familial Juvenile Polyposis

Familial juvenile polyposis (FJP) is a rare autosomal dominant hereditary disorder that is characterized by the development of multiple distinct juvenile polyps in the gastrointestinal tract and an increased risk of cancer. Recently, germline mutations, including mutations in the SMAD4, BMPR1A, PTEN and, possibly, ENG genes, have been found in patients with juvenile polyps. We herein report a family with juvenile polyposis syndrome (JPS) with a novel germline mutation in the SMAD4 gene. A 21-year-old man presented with rectal bleeding and was found to have multiple polyps in his stomach, small bowel, and colon. His mother had a history of gastrectomy for multiple gastric polyps with anemia and a history of colectomy for colon cancer. A review of the histology of the polyps revealed juvenile polyps in both patients. Subsequently, mutation screening in DNA samples from the patients revealed a germline mutation in the SMAD4 gene. The pair had a novel mutation in exon 10 (stop codon at tyrosine 413). To our knowledge, this mutation has not been previously described. Careful family history collection and genetic screening in JPS patients are needed to identify FJP, and regular surveillance is recommended.

Detection of MPL exon 10 mutations in myeloproliferative neoplasms V617F-negative patients / 白血病·淋巴瘤

Objective To explore the frequencies of MPL exon 10 mutations in JAK2 V617F-negative myeloproliferative neoplasms patients. Methods MPLW515K/L was processed through allele-specific PGR combined with direct sequence analysis. The mutations of others MPL exon 10 were detected by single strand conformation polymorphism PGR (PCR-SSCP) combined with direct sequencing. Results Of the 103 patients with JAK2 V617F-negtive myeloproliferative neoplasms patients, 1 carried MPLW515K mutation (TGG→AAG)in PMF; 1 was found to have new mutation (CTGGTGATCGCT insert) in ET and have homozygous mutation. Conclusion JAK2 V617F-negtive myeloproliferative neoplasms patients carried additional mutations in addition to W515K/L mutations in MPL exon 10, but its frequency of mutation is low.