In Western Europe it is present but in generally much lower levels apart from “an instance of 27% in Switzerland’s Upper Rhone Valley.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3039512/
The Walser people are named after the Wallis (Valais), the uppermost Rhône valley, where they settled from roughly the 10th century in the late phase of the migration of the Alamanni, crossing from the Bernese Oberland; because of linguistic differences among the Walser dialects, it is supposed that there were two independent immigration routes.