Originally Posted by
Tomenable
Of course there are also other minor clusters, for example as of year 1824 there were about 200,000 Lithuanians living in East Prussia [the total population of East Prussia was 1,080,000 at that time]. Autosomally they were probably just like Lithuanians in the Russian Empire, but unlike them they were Protestant. These Protestant Lithuanians became Germanized during the 19th century, but their DNA of course still persisted. In the 1939 census East Prussia had 2,490,000 inhabitants - so proportionally about 450,000 should be descended from Lithuanians, even though they were no longer counted as Lithuanians in censuses. During and after WW2 they all moved westward to Germany.
If there are still unmixed descendants of those Lithuanians living in Germany today, they are going to cluster autosomally with Balts. Of course if they mix with West Germans then children are going to be intermediate.
So actually some Germans can be autosomally as far east as Lithuanian-like (Czech-like is not their eastern limit).