The baby was born with a chromosome deficiency and the specialists gave her a life expectancy of up to six months.

deficiency 是由前缀 de-（表示"减少、缺乏"）和词根 fic（来自拉丁语 facere，意为"做"）加上后缀 -iency 构成的名词，字面意思是"做得不够"或"不足"。 在医学语境中，chromosome deficiency 特指"染色体缺陷"，即染色体数量或结构异常导致的遗传问题。