Expanded features of qq()

1. Optional color specification of the points and abline.
(pt.col='black', pt.bg='black', abline.col='red')

2. Optional grid lines.
(grid=TRUE, grid.col='gray88')

3. Optional 95% confidence intervals.
(confidence=TRUE, confidence.col='gray76')

4. Optional highlighting of data points of interest.
(highlight=c('rs20762','rs13895','rs11846'), highlight.col = 'blue', highlight.bg = 'blue')

5. Optional annotation (rs_id) of data points of interest.