Q: How frequent are Asian blood types in Slovakia?
There is no match between the modern linguistic, political, or ethnic maps of Europe and the genetic maps of the continent (some genetic traits in the Basque and Sámi regions are isolated exceptions). Most maps of genetic variations show gradual geographic changes with increasing distance, not an association with the current nations or languages. Calculated genetic averages for individual countries are sometimes at odds with what is seen as their cultural and historical closeness or distance. Modern European languages (including Slovak and other Slavic languages) were superimposed on descendants of a wide range of ancient languages we know nothing about except bits of their speakers' genetic makeup, which has been diffused by migrations and interbreeding.
An example of the multitude of genetic traits that override modern national boundaries may be a remnant of how farmers spread from the south-east into Europe 8-10 thousand years ago. That particular trait is most concentrated in the bottom right corner in the map below and becomes less frequent with each neighboring shaded area (SK marks Slovakia):
Source: L. Luca Cavalli-Sforza, The History and Geography of Human Genes.
The same gradual change across Europe applies to human physiological attributes that may be more common in Asia and less so in Europe. Blood types B and AB, for instance, are more frequent in Asia (although AB is never more frequent than types A and 0). Their frequency gradually drops from east to west in Europe:
Slovakia: a range of estimates for the country and areas; data for north-central Slovakia: Juraj Mitura, Central Military Hospital.