BackgroundFamilial hypercholesterolemia (FH) is an underdiagnosed autosomal dominant genetic disorder that confers high but preventable risk for premature adverse cardiovascular events. Timely diagnosis is limited by low uptake of genetic testing (GT) and cascade testing (CT). This systematic review identifies barriers and facilitators for uptake of GT and CT in FH.MethodFollowing PRISMA guidelines, seven databases were searched for studies on GT/CT in FH. Data reporting standards for qualitative studies were evaluated with COREQ and thematic synthesis was conducted. Of the 387 studies identified, 15 were included (qualitative N = 9, quantitative N = 6). These involved 272,954 respondents (qualitative n = 243, quantitative n = 272,711). COREQ scores ranged from 11 to 21 out of 32.ResultsSynthesis of qualitative data indicated family history of illness, being well informed, and value of GT as key facilitators of GT. Financial concerns, suboptimal clinical care, and no/low value of GT were identified as barriers. Facilitators of CT included responsibility to family, healthcare providers' support for CT, and gains of CT, while barriers included disconnect from family, emotional costs, and no value knowing FH status.Quantitative studies reflect emotional distress avoidance, limited opportunity for family disclosure to invite, lack of knowledge, low communication efficacy, and difficulties accessing testing services as predictors impacting CT.ResultsSynthesis of qualitative data indicated family history of illness, being well informed, and value of GT as key facilitators of GT. Financial concerns, suboptimal clinical care, and no/low value of GT were identified as barriers. Facilitators of CT included responsibility to family, healthcare providers' support for CT, and gains of CT, while barriers included disconnect from family, emotional costs, and no value knowing FH status.Quantitative studies reflect emotional distress avoidance, limited opportunity for family disclosure to invite, lack of knowledge, low communication efficacy, and difficulties accessing testing services as predictors impacting CT.ConclusionBeyond knowledge, perceptions about testing-especially perceived value of testing-emerged to be significantly affecting decisions for GT/CT. Disconnect from family is a maior predictor in CT, reducing the likelihood of probands extending an invitation to their family in support of CT. Future interventions should address barriers and facilitators at interpersonal, clinical and systemic levels to improve FH GT/CT uptake. Additionally, further research in diverse cultural contexts is required to bridge gaps in GT/CT services. Interventions should especially prioritize risk perception education and the development of health communication tools to supplement strong clinical guidance, driving a more patient-centered approach in decisions relating to GT/CT.
