All of the following factors contribute to the differences in complex trait risk predictions between different laboratories, EXCEPT . differing methods of combining risk from multiple genetic variants selection of different genetic variants for risk determination different assessments of environmental factors genotyping of different variants

different assessments of environmental factors

Explanation:

In humans, for predicting the future phenotype of any individual, the PSR is used.

A trait may be defined as the state of a character that is a distinct variation of the phenotypic characteristic of any organism.

The following factors contributes to the differences in the complex trait risk predictions in the different laboratories :

-- differing methods of the combining risk from the multiple genetic variants.

-- genotyping of the different variants.

-- selection of the different genetic variants for such risk determination.

Thus the factor which does not contribute is :

"different assessments of the environmental factors."