RESUMO
BACKGROUND: Localisation of the breakpoints of chromosomal translocations has aided the discovery of several disease genes but has traditionally required laborious investigation of chromosomes by fluorescent in situ hybridisation approaches. Here, a strategy that utilises genome-wide paired-end massively parallel DNA sequencing to rapidly map translocation breakpoints is reported. This method was used to fine map a de novo t(5;6)(q21;q21) translocation in a child with bilateral, young-onset Wilms tumour. METHODS AND RESULTS: Genome-wide paired-end sequencing was performed for approximately 6 million randomly generated approximately 3 kb fragments from constitutional DNA containing the translocation, and six fragments in which one end mapped to chromosome 5 and the other to chromosome 6 were identified. This mapped the translocation breakpoints to within 1.7 kb. Then, PCR assays that amplified across the rearrangement junction were designed to characterise the breakpoints at sequence-level resolution. The 6q21 breakpoint transects and truncates HACE1, an E3 ubiquitin-protein ligase that has been implicated as a somatically inactivated target in Wilms tumourigenesis. To evaluate the contribution of HACE1 to Wilms tumour predisposition, the gene was mutationally screened in 450 individuals with Wilms tumour. One child with unilateral Wilms tumour and a truncating HACE1 mutation was identified. CONCLUSIONS: These data indicate that constitutional disruption of HACE1 likely predisposes to Wilms tumour. However, HACE1 mutations are rare and therefore can only make a small contribution to Wilms tumour incidence. More broadly, this study demonstrates the utility of genome-wide paired-end sequencing in the delineation of apparently balanced chromosomal translocations, for which it is likely to become the method of choice.
Assuntos
Pontos de Quebra do Cromossomo , Neoplasias Renais/genética , Translocação Genética , Ubiquitina-Proteína Ligases/genética , Tumor de Wilms/genética , Adolescente , Sequência de Bases , Mapeamento Cromossômico , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 6/genética , Códon sem Sentido , Primers do DNA/genética , DNA de Neoplasias/genética , Genes do Tumor de Wilms , Predisposição Genética para Doença , Humanos , Masculino , Dados de Sequência MolecularRESUMO
Ergonomics is primarily concerned with improving the performance of man or of man-machine systems. Although many applications have produced evident improvements, the terms of reference and the results are not often expressed in measures that are easily converted into financial savings. However, there is a growing demand for cost-benefit data of ergonomic improvements, and several examples in which the application of ergonomic principles has resulted in tangible benefits, are reviewed. Cases are cited of increases of productivity resulting from equipment redesign and of savings achieved from the reduction of accidents, and from improvements in the working environment. It is concluded that there is, as yet, no large body of well-documented cases of financial savings accruing from the application of ergonomics, due in many cases to the difficulties of costing actual changes in performance in the work situation. The need for further studies is debated, and it is suggested that the use of ergonomic data in a design programme should not necessarily be based on the prediction of financial benefits.
