ABSTRACT
Multiple endocrine neoplasia type 2 (MEN 2) is a genetic syndrome caused by germline mutations in the RET proto-oncogene. These mutations cause changes in either the cysteine-rich extracellular domain or, less commonly, the non-cysteine intracellular domains of the RET protein. The genotype-phenotype correlations of classical cysteine RET mutations have been the subject of several comprehensive reviews. Less is known about the characteristics of the non-cysteine RET mutations. Studies of familial medullary thyroid cancer and MEN 2A kindreds carrying non-cysteine RET mutations have revealed a wide array of phenotypes, variable penetrance, and a diverse clinical course. The observed heterogeneity in disease expression has important diagnostic, therapeutic and prognostic implications. This review summarizes the genotypic and phenotypic characteristics of RET codon 804 mutation, a prototype for the less well-defined non-cysteine RET mutations associated with MEN 2.
Subject(s)
Codon/analysis , Multiple Endocrine Neoplasia Type 2a/genetics , Proto-Oncogene Proteins c-ret , Thyroid Neoplasms/genetics , Adolescent , Adult , Child , Child, Preschool , Cysteine/genetics , Female , Genetic Association Studies , Germ-Line Mutation , Humans , Infant , Male , Middle Aged , Multiple Endocrine Neoplasia Type 2a/surgery , Multiple Endocrine Neoplasia Type 2a/therapy , Penetrance , Point Mutation , Proto-Oncogene Mas , Proto-Oncogene Proteins c-ret/genetics , Proto-Oncogenes , Thyroid Neoplasms/surgery , Thyroid Neoplasms/therapy , Young AdultABSTRACT
The outcome of patients diagnosed myelodysplastic syndromes (MDS) between 1990 and 1997 from William Beaumont Hospital (WBH) was analyzed according to the International Prognostic Scoring System (IPSS) risk categorization. A retrospective study of 195 MDS patients wa s performed. Seventy-nine patients with MDS, in whom a karyotype was obtained and with an adequate follow-up were included in the final analysis. Cases of proliferative CMML (WBC > 12x10(9)/l) were excluded from the study. The overall median survival was 3.1 years, and median survival stratified by IPSS was 3.4, 4.1 and 0.5 years for the INT-1, INT-2 and high risk group and not yet reached for the low risk group. The overall survival by IPSS subcategorization were 6.88, 5.29, 5.30 and 2.12 years for the low, INT-1, INT-2, and high risk groups respectively. Cytogenetics were significant in predicting the overall survival. The IPSS score stratified patients into risk categories for development of AML. The risk of development into AML was 8, 8, 33 and 54% for the low, INT-1, INT-2 and high risk groups, respectively. We conclude that IPSS score can be useful in predicting survival and AML evolution in some MDS patients.
