Gene-environment (GE) interaction has important implications in the etiology of complex diseases that are caused by a combination of genetic factors and environment variables. Several authors have developed GE analysis in the context of independent subjects or longitudinal data using a gene-set. In this paper, we propose to analyze GE interaction for discrete and continuous phenotypes in family studies by incorporating the relatedness among the relatives for each family into a generalized linear mixed model (GLMM) and by using a gene-based variance component test. In addition, we deal with collinearity problems arising from linkage disequilibrium among single nucleotide polymorphisms (SNPs) by considering their coefficients as random effects under the null model estimation. We show that the best linear unbiased predictor (BLUP) of such random effects in the GLMM is equivalent to the ridge regression estimator. This equivalence provides a simple method to estimate the ridge penalty parameter in comparison to other computationally-demanding estimation approaches based on cross-validation schemes. We evaluated the proposed test using simulation studies and applied it to real data from the Baependi Heart Study consisting of 76 families. Using our approach, we identified an interaction between BMI and the Peroxisome Proliferator Activated Receptor Gamma (PPARG) gene associated with diabetes.
Abstract A diagnosis of pancreatic cancer is devastating owing to its poor prognosis, with a 5-year survival rate of only 9%. Currently, most individuals are diagnosed at a late stage when treatment options are limited. Early detection of pancreatic cancer provides the greatest hope for making substantial improvements in survival. The Kenner Family Research Fund in partnership with the American Pancreatic Association has sponsored a series of fora to stimulate discussion and collaboration on early detection of pancreatic cancer. At the first forum in 2014, “Early Detection of Sporadic Pancreatic Cancer Summit Conference,” a strategic plan was set forth by an international group of interdisciplinary scientific representatives and subsequently The Strategic Map for Innovation was generated. The current conference report is the third forum in the series, “Early Detection of Pancreatic Cancer: The Role of Industry in the Development of Biomarkers,” which was held in Boston, Massachusetts, on October 27, 2016. This report provides an overview of examples of innovative initiatives by industry and confirms the critical need for collaboration among industry, government, research institutions, and advocacy groups in order to make pancreatic cancer more easily detectable in its earlier stages, when it is more treatable.
Influence of Inhaled Amiloride on Lung Fluid Clearance in Response to Normobaric Hypoxia in Healthy Individuals
Abstract Background Thirty-four single nucleotide polymorphisms (SNPs) are associated with CLL risk to-date. Moreover, family history (FH) of hematological malignancy has been consistently found to be associated with CLL, with an 8.5-fold increased risk of CLL among first-degree relatives. However, there has not been an evaluation of the interactive effects among genetic factors and FH with CLL risk. Methods We pooled data from 8 CLL case-control studies within the InterLymph Consortium (1499 CLL cases and 2601 controls). We computed a polygenic risk score (PRS), a weighted average of the number of risk alleles across the 34 SNPs, with the weights being the log of the previously reported odds ratio (OR) for each SNP. We categorized the PRS by quintiles using the cutoff points based on the distribution of all InterLymph controls (N=8228). Self-reported FH data was available for 60% of cases and 73% of controls. FH was defined as any hematological malignancy in one or more first-degree relative. Logistic regression was used to estimate ORs and 95% confidence intervals (CIs) adjusted for age, sex, socioeconomic status and study. Results The median age at diagnosis of CLL was 63 years and median age of consent was 60 years in the controls. 67% were male in CLL cases and 57% in controls. As expected, FH was associated with CLL risk (OR= 2.14, CI= 1.60-2.86). The median PRS in the cases was 0.40 and in the controls was -0.36 with the frequency of CLL cases in the upper PRS quintile as 48% while in the lowest quintile only 6%. The PRS was strongly associated with CLL risk (OR= 2.90, CI= 2.35-3.56 for upper versus middle quintile). When jointly modeling FH with PRS, a significant interaction was observed (P=0.03). When stratifying by FH, the upper quintile of the PRS had an 11.8-fold (CI= 3.97-34.8) increased risk relative to those in the middle quintile in the FH+ strata, while a 3.11-fold (CI= 2.35-4.10) increased risk was observed in the FH- strata. Conclusions Our data suggest that the PRS has a strong association with CLL risk and this association varies with FH status. Among those with FH-, the risk of CLL was 3-fold for those with many inherited variants while the CLL risk was much higher than that in those with a FH+. Studies are needed to see whether this PRS stratifies risk among those with monoclonal B-cell lymphocytosis, the CLL precursor condition that affects 5-7% of the general population. Citation Format: Geffen Kleinstern, Silvia de Sanjosé, Nicola Camp, Claire M. Vajdic, Timothy G. Call, Mark Liebow, Dennis Robinson, Neil E. Kay, Julie Cunningham, Yolanda Benavente, Alain Monnereau, John Spinelli, James R. Cerhan, Susan L. Slager. Association of polygenic risk scores and family history with the risk of chronic lymphocytic leukemia (CLL) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4267. doi:10.1158/1538-7445.AM2017-4267
Presymptomatic atrophy in autosomal dominant Alzheimer's disease: A serial magnetic resonance imaging study
Abstract Introduction Identifying at what point atrophy rates first change in Alzheimer's disease is important for informing design of presymptomatic trials. Methods Serial T1‐weighted magnetic resonance imaging scans of 94 participants (28 noncarriers, 66 carriers) from the Dominantly Inherited Alzheimer Network were used to measure brain, ventricular, and hippocampal atrophy rates. For each structure, nonlinear mixed‐effects models estimated the change‐points when atrophy rates deviate from normal and the rates of change before and after this point. Results Atrophy increased after the change‐point, which occurred 1–1.5 years (assuming a single step change in atrophy rate) or 3–8 years (assuming gradual acceleration of atrophy) before expected symptom onset. At expected symptom onset, estimated atrophy rates were at least 3.6 times than those before the change‐point. Discussion Atrophy rates are pathologically increased up to seven years before “expected onset”. During this period, atrophy rates may be useful for inclusion and tracking of disease progression.
The Golgi-localized, gamma ear-containing, ARF-binding (GGA) protein family alters alpha synuclein (α-syn) oligomerization and secretion
Background: Lack of wellness among physicians has been associated with increased risk for physical and mental illness, interpersonal discord, and occupational liability. In academic primary care practices, physician wellness and self-care behaviors have been associated with improved patient outcomes. With the increase in team-based care structures in primary care clinics and residencies there may be opportunities to promote wellness among primary clinicians, particularly among resident physicians who are at increased risk for decreased well being. The primary objective of the study was to test an a priori hypothesis that family medicine residents’ perception of support from preceptor team leads would be associated with wellbeing. A secondary objective of the study was to test a post hoc hypothesis that examined whether the relationship between residents’ perception of support from their preceptor team leads would be associated with residents’ well being, while controlling for self-care behaviors. Methods: Our study utilized a prospective cross-sectional design with purposive sampling to survey family medicine residents. Data were collected in February 2016. The survey was sent out to 58 family medicine residents across three family medicine residencies at Mayo Clinic. The survey response rate was 55% (n=32); Ten (31.3%) residents reported being in their PGY-1, 11 (34.4%) in PGY-2; and 11 (34.4%) in PGY-3; participants included 19 (59.4%) women and 13 (40.6%) men. The Brief Resident Wellness Profile (BRWP) was utilized to assess family medicine residents’ perceived sense of professional accomplishment and mood in the past week. Results: In bivariate correlational analyses, increased perception of support from preceptor team leads (r=.40, P<.01) and reporting a male gender (r=.43, P<.01) was associated with increased resident wellness. In exploratory multivariate analysis, results suggested that while controlling for gender, frequency of self-care behaviors, and perceived preceptor team lead support, a one-point change on rating of perceived team leader support is associated with a 1.69 increase in resident wellness score on the BRWP. Conclusions: Our results provide preliminary evidence to support the relationship between preceptor team lead support and resident wellness in team-based care, above and beyond the impact that self-behaviors have on wellness. Our findings suggest evidence for the subsequent study of the impact of preceptor team lead relationship quality on resident wellness.
Targeted sequencing of established and candidate colorectal cancer genes in the Colon Cancer Family Registry Cohort