Isoline use in crop composition studies with genetically modified crops under EFSA guidance - Short communication.

The European Food Safety Authority (EFSA) oversees the safety evaluation of genetically modified (GM) crops in the European Union. EFSA requires inclusion of commercial non-GM reference lines and a non-GM isoline in crop composition studies with GM crops. Reference lines are used to construct equivalence limits for each compositional analyte. Results for the GM line are compared with these equivalence limits to assess compositional equivalence between the GM crop and the non-GM crop. If compositional equivalence cannot be concluded from this comparison, then results for the non-GM isoline can be used to determine if this finding is likely the result of the background non-GM genetics of the GM crop. If this latter comparison is not sufficient to assess the compositional safety of the GM crop, then a biological-relevance assessment for the analytes in question can be completed taking into account the greater body of knowledge of composition for the crop and diets. Thus, the isoline is a useful comparator but not required to assess the compositional safety of the GM crop, and therefore, unavoidable genotype differences between the isoline and GM line should not be grounds for rejection of compositional studies where the biological relevance of potential non-equivalence is addressed.