OBJECTIVES:
* To determine and define the biological basis of different subtypes of chronic graft-vs-host disease using a targeted single nucleotide polymorphisms approach in patients who have undergone allogeneic stem cell transplantation.
OUTLINE: Two important aspects of the methodologies that will be employed for the analysis of SNPs associated with GVHD are throughput efficiency to be able to perform the assays on a reasonable number of samples as well as having the ability to add or remove SNPs to the assay panel. While a genome-wide association study to identify variants associated with GVHD would offer an unbiased approach, our patient cohort size would not allow significant statistical power in the study. Therefore, a more targeted approach using two established technologies is proposed.
The Sequenome assay uses the unique combination of a single-base primer extension assay incorporating one of four modified nucleotides. The four modified nucleotides each have a unique mass that allows them to be distinguished from one another using mass spectrometry. Each SNP is determined analyzing the primer extension product from a PCR amplicon that surrounds the SNP of interest. The development of each assay involves designing flanking PCR primers and an internal extension assay using web-based software provided by Sequenome. The assays can be designed to analyze up to 30 SNPs in a single reaction, providing a customizable, efficient and high-throughput assay for SNPs of interest.
