Evidence for recombination suppression has been identified in linkage studies of several unstable DNA diseases. Also sex-specific changes in recombination frequency have been detected at the loci of Huntington's disease and myotonic dystrophy. It can be hypothesized that meiotic recombination is regulated by genome-wide genomic imprinting and that changes in meiotic recombination imply the presence of the genomic imprinting defect. If aberrant recombination at the locus of trinucleotide repeat expansion is verified, new theoretical and experimental opportunities will arise in studies on the role of genomic imprinting in the unstable DNA disease.