The possibility that Japanese used words derived from "Mongoloid" to refer to Down Syndrome hadn't crossed my mind until I was mentioning the word to a Japanese person practicing English, but jisho.org mentions the word, and the term is mentioned in the Japanese edition of Wikipedia's entry on Down Syndrome.

Was 蒙古症 or similar terms derived from the English word "Mongoloid" commonly used to refer to Down Syndrome?


2 Answers 2


Apparently Dr. John Langdon Down discovered around 1860 what's now called Down's syndrome. Just like anyone, Dr. Down didn't name the syndrome after himself, but named it "mongolism" (also "mongoloid"), which was used widely until the 1960s. (More info here, at Down's Syndrome Scotland.)

I'm guessing that 蒙古症 is a literal translation from English and was used widely in Japan at least until the 1960s, when it was globally renamed Down's syndrome, citing from the above link

scientists petitioned to use “Down’s syndrome” instead of “Mongolism” or “Mongoloid” as they were embarrassing terms for Chinese and Japanese scientists and academics to use this word to refer to the syndrome

(Unfortunately I don't have access to any Japanese corpus data from before 1960 to confirm this.)

For contemporary Japanese, 大辞泉 has (emphasis mine)


《Down's syndrome》染色体の異常により、知能障害と特異な顔貌(がんぼう)を示す疾患。1866年に英国の医師ダウンが報告。蒙古(もうこ)症。 ダウン症。



大辞林 is a little more politically correct:


⇒ ダウン症候群(しようこうぐん)


〔1866年ダウン(J. Langdon Down 1826~1896)が報告したことからの名〕 染色体異常の一。多くは二一染色体の過剰による。一般に精神発達や発育が障害され,先天性の心疾患を伴うこともある。俗に蒙古症ともいわれた。

That is, 大辞林 says "used to be commonly called mongolism", whereas 大辞泉 lists "mongolism" as an alternative name for "Down's syndrome".


The terms we use most often would be 「ダウン[症候群]{しょうこうぐん}」 or 「ダウン[症]{しょう}」.

I feel like I heard the term 「[蒙古症]{もうこしょう}」 when I was little, but I sure do not hear/see it anymore.

「蒙古症」 would be a direct translation of the desease name from its counterpart in a European language (not sure which one). As we all know now, however, the desease has nothing to do with the race of the patient. Thus, using the term could sound somewhat derogatory and I personally cannot recommend it.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .