There is a possible explanation of the high frequency of U152 at least among Northern Bashkirs in Perm region tested by Myres et al. (2010)
In Bulat Aznabaev’s work "Bashkir society from the XVII century to the first third of the XVIII century.", Ufa, 2016 (in Russian) there is information on incorporation of at least one West European into a Northern Bashkir clan:
“Among the representatives of various ethnic groups included in the structure of the Bashkir clans, there were also groups quite exotic for the region. In 1652, the Bashkirs of the village of Bisert of the Gaynа district named Aktugan and Ilbakhtey, sons of Alish, submitted a complaint against a Bashkir of the same district Afonka, son of Yanmurza, accusing him of invading their own patrimonial land on the Bisert river. During the trial, the defendant stated that the disputed patrimony was bought from the plaintiffs father for 10 rubles.
The plaintiff Aktugan insisted that his father could not sell the patrimony because it was not officially separated from Kushchi clan Bashkirs’ estate, since “his father was a native German (Немчин) and took the land from the Kushchi clan Bashkirs against the obligation to pay Yasak (tax), 57 years ago, and in that case his father gave a record to the Kushchi Bashkirs.”
Thus, back in the 90s of the 16th century, a certain “German" concluded an agreement on the admission to the clan’s land, and his sons in the middle of the XVII century became full-fledged holders of patrimonial estate of the Gayna district. The appearance of a European among the Bashkirs is understandable. A decree dated June 18, 1593 was in force in neighboring Kazan county, according to which the Tatar landowners lost the right to own Russian people. Instead, they were invited to accept or buy "Lithuanians, Latvians, Tatars, and Mordovians." From distant military expeditions, they brought with them captured and bought Germans, Latvians and Lithuanians, and planted them on their lands.
According to the census of the Kazan district by I. Boltin, a German named Anza Kutleyarov lived in the estate of the serving Tatar of Kalmyk origin, Bakshanda Nurushev. A German named Matish lived in the courtyard of the Prince Bagish Yaushev. These foreigners, having fallen into a different environment, subsequently converted to Islam, married Tatar women and assimilated completely with Tatars. In 1646, while describing the estate of Prince Baish Yaushev, the census takers registered a native German Mineyko Bekbulatov, peasant of the village of Minger of the Arsk Road,. It is likely that some of these enslaved Germans, having lost hope of returning to their homeland, at least sought to gain freedom. "
Personally I would like to add that the Russian word «Nemchin» translated here as «German» at the time had the meaning of a Western European in general and not exclusively German.
The full text of the Russian document about Alish’s sons was published in another work. So we know that in 1652 three sons of a native «German» were members of a Northern Bashkir clan Kushchi and had patrimonial estate at the confluence of Bisert and Ufa rivers.