Zhè jǐ zhǒng bìng zài yīxué shàng yǒu yí ge zǒngchēng.
These few diseases have a collective name in medicine.
Tips
usage
Dictionaries and textbooks use the frame X 是 Y 的总称 "X is the general name for Y". 统称 means much the same and also works as a verb, "to be called collectively".
