RESUMO
BACKGROUND: Increased risk of venous thromboembolism (VTE) is a life-threatening side effect for users of oral contraceptives (OCs) or hormone therapy (HT). OBJECTIVES: To investigate the potential for genetic predisposition to VTE in OC or HT users, we conducted a gene-by-environment case-only meta-analysis of genome-wide association studies (GWAS). METHODS: Use or nonuse of OCs (7 studies) or HT (8 studies) at the time of the VTE event was determined by pharmacy records or self-report. A synergy index (SI) was modeled for each variant in each study and submultiplicative/supramultiplicative gene-by-environment interactions were estimated. The SI parameters were first meta-analyzed across OC and HT studies and subsequently meta-analyzed to obtain an overall estimate. The primary analysis was agnostic GWAS and interrogated all imputed genotypes using a P value threshold of <5.0 × 10-8; secondary analyses were candidate-based. RESULTS: The VTE case-only OC meta-analysis included 2895 OC users and 6607 nonusers; the case-only HT meta-analysis included 2434 HT users and 12 793 nonusers. In primary GWAS meta-analyses, no variant reached genome-wide significance, but the smallest P value approached statistical significance: rs9386463 (P = 5.03 × 10-8). We tested associations for 138 candidate variants and identified 2 that exceeded statistical significance (0.05/138 = 3.62 × 10-4): F5 rs6025 (P = 1.87 × 10-5; SI, 1.29; previously observed) and F11 rs2036914 (P = 2.0 × 10-4; SI, 0.91; new observation). CONCLUSION: The candidate variant approach to identify submultiplictive/supramultiplicative associations between genetic variation and OC and HT use identified a new association with common genetic variation in F11, while the agnostic interrogations did not yield new discoveries.
RESUMO
Neither direct-to-consumer (DTC) genetic testing nor predictive genetic testing for adult-onset conditions is recommended for minor children due to ethical concerns and low clinical utility. However, parents with pathogenic variants (PVs) in disease-causing genes may be interested in pursuing genetic testing that includes the familial PV for their children. The Pediatric Testing Attitudes Scale (P-TAS) was previously developed to examine high-risk parents' opinions about pediatric BRCA genetic testing for adult-onset breast/ovarian cancer. Here, the psychometric properties of the P-TAS were examined in a new sample of N = 126 parents (M age = 47.2 years) with PVs in a more complete set of cancer risk genes represented on DTC panel tests. The mean score on the P-TAS was 44 out of a maximum score of 60, indicating that a majority of parents generally held favorable opinions about testing their children for adult-onset inherited cancer syndromes. The internal consistency of the full scale was high (α = 0.91). A factor analysis identified two-component scales, labeled Attitudes and Beliefs (α = 0.93) and Decision Making and Communication (α = 0.83). In a multivariable regression model, P-TAS co-factors accounted for 34% of variance in parental opinions, including the frequency of prior family communication about cancer and the likelihood of utilizing DTC genetic testing with children (R2 = 0.34, p < 0.001). Results suggest that the P-TAS remains a reliable measure to assess high-risk parents' opinions about pediatric DTC genetic testing for adult-onset conditions, with promising validity. Applications of the P-TAS include informing genetic counseling practice, pediatric medical care, and policy guidelines surrounding DTC genetic testing.
