Abstract Background To protect minors’ future autonomy, professional organizations have historically discouraged returning predictive adult-onset genetic test results and carrier status to children. Recent clinical guidance diverges from this norm, suggesting that when minors have genomic sequencing performed for clinical purposes, parents and children should have the opportunity to learn secondary findings, including for some adult-onset conditions. While parents can currently opt in or out of receiving their child’s secondary findings, the American Society of Human Genetics Workgroup on Pediatric Genetic and Genomic Testing suggests including adolescents in the decision-making process. However, it is not clear what factors young people consider when given the opportunity to learn genetic findings for themselves. We are examining adolescents’, young adults’, and parents’ (if applicable) decisions about learning genomic information for the adolescent. Methods We are enrolling assenting (ages 13–17) adolescents and consenting (ages 18–21) young adults in a prospective genomic screening study to assess the choices they make about receiving individual genomic results. Participants use an online tool to indicate whether they want to learn their personal genetic risk for specific preventable, treatable, and adult-onset conditions, as well as carrier status for autosomal recessive conditions. We are examining 1) how choices differ between adolescent and young adult cohorts (as well as between adolescents/young adults and parents) and 2) decisional conflict and stability across study timepoints. Results are returned based on participants’ choices. Qualitative interviews with a subset of participants explore decisional stability, adolescent/young adult engagement with parents in decision-making, and the impact of learning pathogenic/likely pathogenic and carrier results. Discussion This study explores decision making and decision stability between adolescents and parents (where applicable), as well as the ethical implications and impact of return of clinical-grade genetic research results to adolescents and young adults. The results of this study will contribute empirical evidence to support best practices and guidance on engaging young people in genetic research studies and clinical care that offer return of results. Trial Registration: ClinicalTrials.gov Identifier: NCT04481061. Registered 22 July 2020.
Abstract 181: Meta-Analysis of Genome-Wide Association Studies Identifies Two New Susceptibility Loci for Intracerebral Hemorrhage
Background: Intracerebral hemorrhage (ICH) is the stroke subtype with the worst prognosis and has no established acute treatment. ICH is classified as lobar and non-lobar based on the location of the hemorrhage, with genetic variation contributing to risk of both subtypes. We report the first genome wide association study (GWAS) of this condition. Methods: The discovery phase included GWAS data (Illumina 610 or Affymetrix 6.0) from 6 ICH studies that enrolled subjects of European ancestry in the US and Europe. Cases were classified as lobar or non-lobar ICH based on head CT. ICH-free controls were selected from ambulatory clinics or by random digit dialing. Standard quality controls filters were applied and principal component analysis was used to account for population structure. Unobserved genotypes were inferred by imputation to 1000 genomes references panels. Association testing was carried out using logistic regression, assuming additive effects, and including age, gender and principal components in the model. Meta-analyses were completed using the inverse normal method, weighting by sample size. Replication of signals with p<1x10E-6 was pursued in an independent multi-ethnic study utilizing direct genotyping. Results: The discovery phase included 1545 cases (664 lobar and 881 non-lobar) and 1481 controls, and tested 5,358,103 SNPs. Two loci were identified: for lobar ICH, an intergenic region located on chromosome 12q21.1 (rs11179580: minor allele frequency [MAF] 0.22, OR 1.54, 95% CI 1.33 - 1.84; p = 6.7x10E-8); and for non-lobar ICH, a region on chromosome 1q22 encompassing the PMF1 and SLC25A44 genes (rs2984613: MAF 0.31, OR 1.45, 95% CI 1.2 - 1.64; p = 8.9x10E-9). Replication included 1256 cases (329 whites, 506 blacks and 421 Hispanics) and 760 controls (237 whites, 346 blacks and 177 Hispanics) and confirmed both loci: 12q21.1 (p = 0.037, meta-analysis p = 2.3x10E-8) and 1q22 (p = 3.0x10E-4, meta-analysis p = 2.2x10E-11). Conclusions: Two new susceptibility loci for ICH were identified, both showing location-specificity. These results confirm the presence of biological heterogeneity across ICH subtypes and highlight that different genetic risk factors may contribute to the small vessel diseases that underlie each ICH subtype.