Validation of cystic fibrosis mutation analysis using ABI 3130XL genetic analyzer

Cystic fibrosis (CF) is one of the most common autosomal recessive diseases in the white population, with a prevalence estimate of 1 in 2500 to 3300 live births. CF is characterized by viscous mucus in the lungs with involvement of digestive and reproductive systems as well as sweat glands (excess salt loss). Treatment for CF patients is palliative. Over 1300 mutations have been identified in the CFTR gene. However, most of the mutations are at frequencies of <0.1% or represent private mutations. Although other methodologies are available for CF testing, the oligonucleotide ligation assay is a unique approach to mutation detection of point mutations, small deletions, and small insertions, and consists of 2 phases. Applied Biosystems 3130 Series Genetic Analyzers are the next-generation platform for low to medium throughput laboratories and deliver improved performance. One disadvantage of the Genetic Analyzers is that there is no template of instrument settings for POP-6 polymer using 36-cm array. The Abbott CF oligonucleotide ligation assay ASRs can be run only using POP-6 polymer. We are the first to have optimized the instrument settings for POP-6 polymer based on the template of Rapidseq36-POP6 for Abbott Diagnostics CF V3 ASRs. Several conditions were tried, and the conditions of sample injection voltage at 10,000 v and sample injection time at 5 seconds gave better results, which were with clearer peaks and lower background signals. Twenty cell line DNA samples from Coriell were analyzed, and the results were matched. In addition, Synthetic Controls from AcroMetrix were analyzed, and the results were same as expected. Also, about 1500 clinical samples were analyzed, and high-quality reportable results were obtained. In conclusion, our modified protocol is robust and reliable on this ABI 3130XL instrument.