ABSTRACT
We developed a procedure for DNA extraction from small volumes of fixed cell suspensions previously prepared for conventional cytogenetic analysis. Good quality DNA was isolated with a fast and simple protocol using DNAzol reagent. This provided suitable DNA for various types of molecular analyses, including polymerase chain reaction, restriction fragment length polymorphism, denaturing high-performance liquid chromatography, and direct sequencing. This technique provides sufficient material for such test, which are important for diagnosis of neoplastic diseases in pediatric patients.
Subject(s)
Humans , Cytogenetics/methods , DNA , Genome , Neoplasms/diagnosis , Sequence Analysis, DNA/methods , Chromatography, High Pressure Liquid/methods , Exons , Karyotyping , Neoplasms/genetics , Polymerase Chain Reaction , Polymorphism, Restriction Fragment LengthABSTRACT
O estudo citogenético convencional em uma menina com aniridia esporádica resultou em uma aparente translocaçäo balanceada t(11;13)(p13;q33) de novo. Entretanto, o estudo citogenético pela hibridaçäo in situ fluorescente (FISH) detectou a presença de uma deleçäo críptica 11p13p14, incluindo a regiäo WAGR e envolvendo aproximadamente 7.5 Mb de DNA, deletando os genes PAX6 e WT1. Estes resultados correlacionam-se com o quadro clínico da paciente e a coloca em alto risco de desenvolver tumor de Wilms. A ausência de retardo mental na paciente indica que a posiçäo distal do ponto de quebra poderá refinar o mapeamento do locus retardo mental na síndrome de genes contíguos WAGR (Wilms, aniridia, anomalias genitais e retardo mental).