Van Zeeland et al (2013) Flashcards
what were the aims?
to look at a number of genes which they thought might play a role in AN using a candidate gene approach as the genes are candidates for contributing to disease risk.
what did the researchers focus on?
the researchers focused on the EPHX2 gene, which is involved in cholestrol function and individuals with AN often show high cholestrol levels that return to normal when they put weight on.
who were their ppts?
studied the DNA from 1,205 people with AN and 1,948 people without.
what was the main ppts?
they started with 262 white european women with early onset AN and 80 matched controls.
- they had been clinically diagnosed with a history of restricting type anorexia and were average of 14 yrs when they first experienced it.
-women who reported regular binge eating were not included in the sample, to ensure similarity.
what was the procedure?
after this they tested their findings in 500 AN cases and 500 controls and also data on a further 444 cases of AN or eating disturbances.
- this method is known as a replication sample of looking for associations in one sample and then confirming what you find in another sample.
what were the results?
- the two variants which showed the strongest association with AN were in the estrogen receptor beta gene
- another form of analysis looked at groups of variants together and in two genes (ITPR3 and EPHX2) showed the strongest association with AN.
- one of the variants in EPHX2 was related to how BMI and cholestrerol levels changed over time
what was the conclusion?
they had identified a novel association of gene variants within EPHX2 to susceptibility to AN and provide a foundation for future study of this important yet poorly understood condition
what is a strength of the ppts?
the use of a control group increases the validity and reliability of the findings because the group acts as a baseline measurement, through which comparisons can be made
- sample size of 800 ppts in total increases the reliability of the conclusions drawn because it is less likely that the observed findings are due to chance
what is a weakness?
the EPHX2 gene is only one specific gene, whereas hundreds of which contribute to the development of AN, alongside environmental influences
