title: RAS and FMS mutations following cytotoxic therapy for childhood acute lymphoblastic leukaemia.
abstract: Patients who have received cytotoxic therapy for primary neoplastic disease are at an increased risk of developing secondary (therapy-related) acute myeloid leukaemia (AML) or myelodysplasia (MDS). RAS and FMS mutations have been observed in patients with AML and MDS. It has been suggested that the mutational status within these genes may be predictive of early secondary leukaemic disease. In this study we have screened 50 haematologically normal patients in complete remission from childhood acute lymphoblastic leukaemia (ALL) for activating point mutations in the RAS and FMS proto-oncogenes. Such patients may be considered at risk of therapy-related disease. Codons 12, 13 and 61 were screened in RAS and codon 969 in FMS using the polymerase chain reaction (PCR) followed by oligonucleotide hybridization (ONH). Three of the 50 patients (6%) were found to harbour N12 RAS mutations. One of these three patients (2%) had both a N12 RAS and FMS 969 mutation. Upon sequencing the RAS mutations, substitutions of serine, cysteine and aspartic acid for glycine were identified. The FMS 969 mutation was also confirmed, by sequencing, as a histidine substitution. RAS mutations were not detected in presentation samples indicating that these lesions have been somatically acquired presumably subsequent to cytotoxic therapy for the primary disease. Continued follow-up of these patients may indicate a role for these mutations in the development of secondary malignancies.
authors.affiliation: Haematology Department, University of Wales College of Medicine, Health Park, Cardiff, UK.
authors.forename: C
authors.initials: C
authors.lastname: Taylor
authors.forename: H
authors.initials: H
authors.lastname: McGlynn
authors.forename: G
authors.initials: G
authors.lastname: Carter
authors.forename: A H
authors.initials: AH
authors.lastname: Baker
authors.forename: N
authors.initials: N
authors.lastname: Warren
authors.forename: S A
authors.initials: SA
authors.lastname: Ridge
authors.forename: G
authors.initials: G
authors.lastname: Owen
authors.forename: E
authors.initials: E
authors.lastname: Thompson
authors.forename: P W
authors.initials: PW
authors.lastname: Thompson
authors.forename: A
authors.initials: A
authors.lastname: Jacobs
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D001483:Base Sequence; D002648:Child; D003062:Codon / Q000235:genetics; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000235:genetics; D016236:Genes, fms / Q000187:drug effects; D011905:Genes, ras / Q000187:drug effects; D006801:Humans; D008969:Molecular Sequence Data; D016609:Neoplasms, Second Primary; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D012074:Remission Induction; D012307:Risk Factors
chemical_list: D003062:Codon; D004273:DNA, Neoplasm