title: Psychological impact of genetic testing for familial hypercholesterolemia within a previously aware population: a randomized controlled trial.
abstract: This trial tests the hypothesis that confirming a clinical diagnosis of familial hypercholesterolemia (FH) by finding a genetic mutation reduces patients' perceptions of control over the disease and adherence to risk-reducing behaviors. Three hundred forty-one families, comprising 341 hypercholesterolemia probands and 128 adult relatives, were randomized to one of two groups: (a) routine clinical diagnosis; (b) routine clinical diagnosis plus genetic testing (mutation searching in probands and direct gene testing in relatives). The main outcome measures were perceptions of control over hypercholesterolemia, adherence to cholesterol-lowering medication, diet, physical activity, and smoking. There was no support for the main hypothesis: finding a mutation had no impact on perceived control or adherence to risk-reducing behavior (all P-values > 0.10). While all groups believed that lowering cholesterol was an effective way of reducing the risk of a heart attack, participants in whom a mutation was found believed less strongly in the efficacy of diet in reducing their cholesterol level (P = 0.02 at 6 months) and showed a trend in believing more strongly in the efficacy of cholesterol-lowering medication (P = 0.06 at 6 months). In conclusion, finding a mutation to confirm a clinical diagnosis of FH in a previously aware population does not reduce perceptions of control or adherence to risk-reducing behaviors. The pattern of findings leads to the new hypothesis that genetic testing does not affect the extent to which people feel they have control over a condition, but does affect their perceptions of how control is most effectively achieved. Further work is needed to determine whether similar results will be obtained in populations with little previous awareness of their risks.
authors.affiliation: Psychology & Genetics Research Group, King's College London, London, United Kingdom. theresa.marteau@kcl.ac.uk
authors.forename: Theresa
authors.initials: T
authors.lastname: Marteau
authors.forename: Victoria
authors.initials: V
authors.lastname: Senior
authors.forename: Steve E
authors.initials: SE
authors.lastname: Humphries
authors.forename: Martin
authors.initials: M
authors.lastname: Bobrow
authors.forename: Treena
authors.initials: T
authors.lastname: Cranston
authors.forename: Martin A
authors.initials: MA
authors.lastname: Crook
authors.forename: Lorna
authors.initials: L
authors.lastname: Day
authors.forename: Maryam
authors.initials: M
authors.lastname: Fernandez
authors.forename: Rob
authors.initials: R
authors.lastname: Horne
authors.forename: Andrew
authors.initials: A
authors.lastname: Iversen
authors.forename: Zoe
authors.initials: Z
authors.lastname: Jackson
authors.forename: Jacqui
authors.initials: J
authors.lastname: Lynas
authors.forename: Helen
authors.initials: H
authors.lastname: Middleton-Price
authors.forename: Richard
authors.initials: R
authors.lastname: Savine
authors.forename: Jim
authors.initials: J
authors.lastname: Sikorski
authors.forename: Melanie
authors.initials: M
authors.lastname: Watson
authors.forename: John
authors.initials: J
authors.lastname: Weinman
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Wierzbicki
authors.forename: Richard
authors.initials: R
authors.lastname: Wray
mesh_terms: D000328:Adult; D000368:Aged; D001364:Awareness; D004644:Emotions; D005260:Female; D005820:Genetic Testing / Q000523:psychology*; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000175:diagnosis* / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics