Scott Topper, Viswateja Nelakuditi, Melissa A. Dempsey, Jelena Brezo, Soma Das

The genetic diagnosis of non-syndromic neurological disease presents unique challenges to clinicians and diagnostic labs: recognizable phenotypes may be genetically heterogeneous with many dozens of genes causally implicated, mutations in each gene may only explain a negligible percentage of patient cases, and a complex and rapidly developing literature requires constant re-evaluation of the diagnostic strategy.    Here, we present a highly multiplexed approach to the diagnosis of non-syndromic mental retardation, developmental delay, and brain malformations.  In collaboration with clinicians and genetic counselors, we developed an initial panel of 98 potentially causative genes, and developed a schedule for the periodic re-evaluation and expansion of the panel.  Using the Raindance microdroplet DNA enrichment platform, we amplified 1627 coding exons (in 2663 amplicons), for multiplexed, paired-end sequencing on an Illumina GaIIx.  We present the details of successful identification of a causative mutation in the AGTR2 gene in a patient with mental retardation and early infantile seizures in whom extensive testing had previously been performed and found to be normal.  We also present results of multiplexing this technology on an additional 12 patients, the results of our large-scale validation experiments, identification and elimination of technical artifacts unique to the Raindance amplification process, and sample handling and validation concerns towards certifying this approach as a diagnostic technique.  Concurrent work is exploring targeted bead capture methods as well as exome capture, and our experience with these different platforms will be presented. 

This poster (#464) will be presented by Scott Topper Saturday March 19: 10:30-11:30am.  Stop by and learn more.