POSTERS ABSTRACTS 1 New Biotechnology · Volume 27S · April 2010 Figure 3 Phylogenetic relationships between members of family Fasciolidae. (*): Query sequence as Fasciolopsis buski. Figure 4 Phylogenetic relationships between members of family Fasciolidae. (*): Query sequence as Fasciola gigantica. doi:10.1016/j.nbt.2010.01.026 [P1.20] Genetic and epigenetic variation and toxicity and/or outcome during therapy in childhood acute lymphoblas- tic leukemia E. Lopez-Lopez 1,4,* , I. Martin-Guerrero 1,4 , J. Ballesteros 1,4 , J. Uriz 2,4 , N. Garcia de Andoin 2,4 , M.A. Pinan 3,4 1 University of the Basque Country, Spain 2 Hospital Donostia, Spain 3 Hospital de Cruces, Spain 4 Hospital La Paz, Spain Acute lymphoblastic leukemia (ALL) is the most common child- hood cancer, and still an important cause of cancer-related death in children. Although the introduction of treatment protocols has improved survival, interindividual differences in drug responses are an important cause of resistance to treatment and adverse drug reactions. Pharmacogenetic studies are providing a rational base for further treatment efficacy and reduction of complications. The aim of the present study was to determine if there was a correlation between genetic and epigenetic variation and toxicity and/or outcome during therapy in paediatric ALL patients. We analyzed genetic polymorphisms and epigenetic variations of 12 genes in paediatric ALL patients: 6 genes of the MTX path- way (MTHFR, TYMS, SHMT1, RFC1, ABCB1 and ABCG2), 1 gene of the 6-MP pathway (TPMT) and 5 genes involved in xenobiotic detoxification (CYP1A1, NQO1 and the GSTs GSTM1, GSTT1 and GSTP1). Several associations were found between polymorphisms and clinical parameters, such as that of the MTHFR C677T and A1298C polymorphisms and hepatotoxicity and gastrointestinal toxicity respectively. S28 www.elsevier.com/locate/nbt