ABSTRACT
CONTEXT: Mutations of the p53 tumor suppressor gene are the most frequent alterations observed in human neoplasias affecting adults. In pediatric oncology, however, they have seldom been identified. WilmsÆ tumor is a renal neoplasia commonly occurring in children and is associated with mutations of the WT1 gene. The correlation between WilmsÆ tumor and alterations of the p53 gene has not been well established, with a low frequency of mutations having been reported in this type of tumor. Mutation may be associated with advanced stage disease and unfavorable histology. OBJECTIVE: To screen for mutations of the p53 gene by the PCR-SSCP method and DNA sequencing in cases of WilmsÆ tumor sug-gestive of mutation. DESIGN: Case Report. CASE REPORT: Evaluations of exons 5-9 of the p53 gene in DNA samples extracted by PCR-SSCP from 10 WilmsÆ tumors in children at different stages, and DNA sequencing. Changes in SSCP analy-sis were observed in exon 8 in two samples. The probable muta-tions were not confirmed by DNA sequencing. The absence of point mutations in p53 gene observed in the 10 samples of WilmsÆ tumor studied agrees with literature data, with DNA sequencing being of fundamental importance for the confirmation of possible mutations
Subject(s)
Humans , Infant , Child, Preschool , Child , Male , Female , Genes, p53/genetics , Wilms Tumor/genetics , Kidney Neoplasms/genetics , Mutation/genetics , Polymerase Chain Reaction/methods , Sequence Analysis, DNA , Polymorphism, Single-Stranded ConformationalABSTRACT
Os autores analisam citigeneticamente doze caos de leucemia näo-linfóide aguda da infância (LNLA), objetivando estabelecer correlaçöes entre alteraçöes cromossômicas, evoluçäo e progressäo da doença. 91,66 por cento dos casos exibiam anomalias. Dois pacientes com classificaçäo FAB M1 e M2 apresentaram translocaçäo t(8;21), associada à monossomia do X e à trissomia desse cromossomo, mais alteraçäo do 7, respectivamente. Ambos faleceram, o primeiro após transplante de medula óssea com recidiva da doença e o segundo com septicemia, confirmando o caráter agerssivo dessa translocaçäo quando associada a outras alteraçöes cromossômicas. Em um dos casos a presença de alteraçöes cromossômicas complexas foi fundamental p[ara a confirmaçäo diagnóstica de eritroleucemia. Cinco pacientes exibiram alteraçöes cromossômicas primárias e seis do tipo secundário. No grupo com alteraçöes primárias se encontram os três pacientes vivos livres da doença. No grupo com alteraçöes secundárias, todos foram a óbito, dois por recidiva, dois por resistência à doença e dois por septicemia, após entrar em remissäo...