Single nucleotide polymorphism and mutation identification by microelectronic chip technology

Background. The need of developing advanced methodologies; for mutation identification has been raising in the last few years. This is principally due to the identification of an increasing number of genetic variations associated with human diseases. Microarrays are a modern DNA diagnostic tool, allowing the rapid analysis of a large cohort of patients for a huge number of allelic variants. Methods. In the present study we have employed a new microelectronic based technology: the NMW 1000 NanoChip™ Molecular Biology Workstation (Nanogen, San Diego, CA), that enables the active movement of charged molecules to designated test sites. We developed assays for the identification of some common Italian mutations in the retina-specific ABC transporter (ABCA4) gene, involved in Stargardt disease. Assays were validated by a retrospective study on a large number of wild type and mutated samples. Results. Comparison of the results obtained with the Nanogen technology and those obtained with other methods showed a complete concordance. Conclusions. In our experience, the microelectronic technology developed by Nanogen allowed to overcome some of the limitations due to passive hybridization. This, coupled to the possibility of assembling different combinations of specific probes onto a microchip to perform customized analyses, could improve the efficiency of mutation identification in a variety of genetic diagnostic applications.