Position Enrichment Test

Question

[Nicolas Rosewick]

Hi,

I've several samples, each of it containing multiple genomic position of interest. Which statistical test can I use to assess enrichment of specific genomic regions ?

For example here three sample with 3 position

A    B    C
100    100    100
200    300    300
1000    500    2000

So here 100 is a position that is enriched .

Thanks

[Devon Ryan]

I guess it depends on what you're comparing against to determine enrichment. What's the genesis of these numbers? Is the background distribution of positions assumed to be random?

[Nicolas Rosewick]

these positions are fusion event positions

Answer 1

[Sean Davis]

Many folks in this situation would use simple thresholds for "enrichment" since the background (null hypothesis) is not well understood. In your data, for example, one might argue that even two samples sharing a position would constitute "enrichment", such as position 300. In the context of NGS data, many fusion event detection algorithms have problems with a high false-positive-rate, so even after filtering for recurrence, there may be further filters that need to be applied (uniqueness of region, mapping quality, coverage of individual fusion events, split-read support, etc.).