Medical Genetics In the first part of the twentieth century, there was much speculation of the cause of down syndrome. The first people to speculate that it might be due to chromosomal abnormalities were Waardenburg and Bleyer in the 1930sMedical Genetics In the first part of the twentieth century, there was much speculation of the cause of Down syndrome. The first people to speculate that it might be due to chromosomal abnormalities were Waardenburg and Bleyer in the 1930s