To investigate their possible roles in disease susceptibility and some disease
characteristics we genotyped C3435T and G2677T/A polymorphisms in multidrug
resistance-1 (MDR1) gene with a single base extension method and the G34A and
C421A polymorphisms of the breast cancer resistance protein gene with an allelic
discrimination system in 396 children with acute lymphoblastic leukaemia (ALL)
and 192 control patients. While the distribution of individual alleles and
genotypes did not differ between patients and controls, there were significant
differences in the frequencies of some rare haplotypes and genotype combinations
in the MDR1 gene between the two groups.