The "theory" on Hun origin of Hakka was based on very fragmentary blood typing and DNA analysis done by Japanese and Russian researchers.

According to DNA typing by Hideo Matsumoto (1966) who gathered blood from China, Korea, Rusia, Taiwan, and Southeast Asia countries and found the folloiwng: [extracted from Kiang's book]
¡@

GM genes
¡@ AG AxG ABST AFBB
North Mongoloids (Koreans, Japanese, Hakka) 45% 15% 25% 15%
Malaysian, Polynesian, Southern Chinese

10%
5% 85%
Burma, Assam, Tibetan, Nepal, Malayo-Polynesian ~0% ~100%

The author thus concludes that Hakkas like Koreans and Japanese were from Baikal Lake as a subgroup of the Altaic people.