alpha

Genetic Components of Alcoholism

Levels of expressed alpha synuclein mRNA in three groups of allele lengths of NACP-REP1.

Usage

alpha

Details

Various studies have linked alcohol dependence phenotypes to chromosome 4. One candidate gene is NACP (non-amyloid component of plaques), coding for alpha synuclein. B<U+00F6>nsch et al. (2005) found longer alleles of NACP-REP1 in alcohol-dependent patients compared with healthy controls and reported that the allele lengths show some association with levels of expressed alpha synuclein mRNA.

Format

A data frame with 97 observations on 2 variables.

alength

allele length, a factor with levels "short", "intermediate" and "long".

elevel

expression levels of alpha synuclein mRNA.

References

Hothorn, T., Hornik, K., van de Wiel, M. A. and Zeileis, A. (2006). A Lego system for conditional inference. The American Statistician 60(3), 257--263. 10.1198/000313006X118430

Winell, H. and Lindb<U+00E4>ck, J. (2018). A general score-independent test for order-restricted inference. Statistics in Medicine 37(21), 3078--3090. 10.1002/sim.7690

Aliases

• alpha

Examples

# NOT RUN {
## Boxplots
boxplot(elevel ~ alength, data = alpha)

## Asymptotic Kruskal-Wallis test
kruskal_test(elevel ~ alength, data = alpha)

## Asymptotic Kruskal-Wallis test using midpoint scores
kruskal_test(elevel ~ alength, data = alpha,
             scores = list(alength = c(2, 7, 11)))

## Asymptotic score-independent test
## Winell and Lindbaeck (2018)
(it <- independence_test(elevel ~ alength, data = alpha,
                         ytrafo = function(data)
                             trafo(data, numeric_trafo = rank_trafo), 
                         xtrafo = function(data)
                             trafo(data, factor_trafo = function(x)
                                 zheng_trafo(as.ordered(x)))))

## Extract the "best" set of scores
ss <- statistic(it, type = "standardized")
idx <- which(abs(ss) == max(abs(ss)), arr.ind = TRUE)
ss[idx[1], idx[2], drop = FALSE]
# }