Jan Jansky Czech serologist, neurologist and psychiatrist. Date of Birth: 03.04.1873 Country: Czech

Biography of Jan Jansky

Jan Jansky was a Czech serologist, neurologist, and psychiatrist who is known for his groundbreaking work in blood classification. He studied medicine at Charles University and began working at the Prague Psychiatric Clinic in 1899. In 1914, he was appointed as a professor.

During World War I, Jansky served as a military doctor until he was demobilized due to a heart attack. After the war, he worked as a neuropyschiatrist in a military hospital. Jansky suffered from angina pectoris and ultimately died from ischemic heart disease.

Jansky was a strong advocate for voluntary blood donation. As part of his psychiatric research, he attempted to establish a correlation between mental disorders and blood diseases. However, he did not find such a connection and published his work titled "Hematologická studie u psychotiků" (Hematological Study on Psychotics) in 1907. In this publication, he also classified blood into four groups: I, II, III, and IV. At the time, this fact went unnoticed.

In 1921, the American Medical Association recognized Jansky's priority in the classification of blood into four groups, surpassing the work of Karl Landsteiner, who had only classified blood into three groups. Landsteiner received the Nobel Prize in 1930 for his discovery. However, Jansky's classification continues to be used to this day.

William Lorenzo Moss also identified four blood groups, but he designated groups I and IV in opposition to Jansky's system. This led to errors in blood transfusions until the standard use of the symbols "A," "B," and "O" became prevalent.