Prenatal exposure to low levels of methylmercury does not affect child cognition, but certain gene variants may increase susceptibility. These are the main conclusions of a study led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by "la Caixa," in collaboration with the Harvard T.H. Chan School of Public Health and the University of Bristol.
source https://www.lifetechnology.com/blogs/life-technology-news-blog/up-to-30-of-children-carry-a-gene-variant-that-may-increase-susceptibility-to-methylmercury