The aberrant phenotype is characterized by the progressive expression of abnormal traits during vegetative growth affecting leaf thickness, shape and/or plant vigour. These striking morphological abnormalities do not appear to be caused by agronomical practices or pathogen infections. Furthermore, the aberrant phenotype, which is observed in 3-20% of cultivated cauliflowers, is not linked to DNA sequence or structural polymorphisms. To detect candidate genes related to the aberrant phenotype, we used amplified fragment length polymorphism on cDNA approach, sampling normal and aberrant F(1) hybrid plants several times before and after the expression of the aberrant phenotype. This screen led to the detection of 51 differentially expressed transcripts. Twenty-nine of these were homologous to annotated genes in genomic databases. We identified transcripts, which were differentially expressed before the expression of the aberrant trait with homology to genes involved in various abiotic stress responses. A non-specific lipid transfer protein homologue was also identified and given the role that these proteins play in epicuticular wax formation and leaf morphology, it may be implicated in the abnormal leaf shape phenotypes.