Pi S Y, Fineman R M, Wing S D, Grunnet M, Chan G
Am J Med Genet. 1980;5(2):201-6. doi: 10.1002/ajmg.1320050214.
Gross malformation of the central nervous system (CNS) is rare in Down syndrome (DS). To our knowledge we report for the first time the association of trisomy 21 and holoprosencephaly. Because of the low probability of chance concurrence due to unrelated causes, a causal relationship between these two conditions in the patient must be presumed. The anatomic similarity of the holoprosencephalic defect in this infant to that seen in others with autosomal dominant, recessive, sporadic, or syndromal forms of holoprosencephaly, supports the hypothesis that: a) this CNS defect is a causally nonspecific developmental field complex (DFC); b) the increased incidence of such DFC's in the DS represents the result of a nonspecific decrease of developmental homeostasis [Waddington, 1975] due to autosomal aneuploidy.
中枢神经系统（CNS）严重畸形在唐氏综合征（DS）中较为罕见。据我们所知，我们首次报告了21三体与前脑无裂畸形的关联。由于非相关原因导致的偶然并发概率较低，必须假定该患者这两种情况之间存在因果关系。该婴儿前脑无裂畸形缺陷与其他常染色体显性、隐性、散发性或综合征性前脑无裂畸形患者所见缺陷的解剖学相似性，支持了以下假设：a）这种中枢神经系统缺陷是一种因果非特异性发育场复合体（DFC）；b）唐氏综合征中此类DFC发病率的增加代表了由于常染色体非整倍体导致的发育稳态[沃丁顿，1975]非特异性降低的结果。
