# Proportion of phenotype in populatuion

**URL:** <https://discourse.datamethods.org/t/proportion-of-phenotype-in-populatuion/16287>\
**Category:** data analysis\
**Tags:** genetics, proportions\
**Created:** [June 23, 2024, 5:36am UTC](https://discourse.datamethods.org/t/proportion-of-phenotype-in-populatuion/16287 "2024-06-23T05:36:30Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jlevy13](https://discourse.datamethods.org/user_avatar/discourse.datamethods.org/jlevy13/32/1892_2.png) [@jlevy13](https://discourse.datamethods.org/u/jlevy13)\
**Post date:** [June 23, 2024, 5:36am UTC](https://discourse.datamethods.org/t/proportion-of-phenotype-in-populatuion/16287/1 "2024-06-23T05:36:30Z")

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Helllo,  
I am dealing with the following problem and would like to ask for your opinion and help.  
I am looking at a population where large portion of the population have a certain genotype G. Some of the carriers present a certain medical condition M, which is suspected to be a phenotype (it is possible that other factors are involved). The initial goal is to determine if the proportion of M in the population of G carriers is (in some sense) “large”.

Also, note that testing for G is not routine, and the test result can be of course positive or negative (we can assume 100% accuracy/precision etc.). The reasons for reffering a patient to test for G are more or less the same for both positives and negatives, and therefore we can assume that the populations fo positives and negatives are similar.

We consider the following aproaches:

1. Match the carriers to a cohort from the general population (and then should we include the G-negarive in the general population?
2. Compare the G-positives to the G-negative.
3. We know **the real proportion of M** in the general population (we have the full data), and therefore we can consider the proportion of M as a constant and proceed accordingly.

Thank you for your help!