Koulischer L, Gillerot Y
Hum Genet. 1980;54(2):243-50. doi: 10.1007/BF00278979.
During the 8 year-period 1971-1978 inclusive, 268 newborn with Down's syndrome (DS) were ascertained in Wallonia (South Belgium). The chromosomes of all patients were analyzed. A standard trisomy 21 was observed in 259 cases (96.6%) and translocations in seven (2.6%). One mosaic (0.4%) and one case with a 47,XX,+21,5 p-karyotype (0.4%) were also found. The overall incidence at birth for the 8 year-period was of 0.123%. However, the comparison of the 2 four-year periods 1971-1974 and 1975-1978 showed an increased incidence in mothers below 35 during the second period, reaching a statistical significant level in Charleroi, and industrial and densely populated area of the region (Fisher's exact test: P = 0.016 less than 0.025). Young women have now become the principal source of DS patients in Wallonia. This change from the previous pattern happened abruptly in 1975, and strongly suggests that one or more persisting factors relating to meiotic non-disjunction of chromosome 21 are operating in this region since 1974, and affecting DS births from 1975 onwards.
在1971年至1978年这8年期间（含1971年和1978年），在比利时南部的瓦隆地区确诊了268例唐氏综合征（DS）新生儿。对所有患者的染色体进行了分析。259例（96.6%）观察到标准的21号染色体三体，7例（2.6%）为易位。还发现1例嵌合体（0.4%）和1例核型为47,XX,+21,5p-的病例（0.4%）。这8年期间的总体出生发病率为0.123%。然而，对1971 - 1974年和1975 - 1978年这两个四年期进行比较发现，在第二个时期，35岁以下母亲所生唐氏综合征患儿的发病率有所上升，在该地区的工业密集且人口稠密的沙勒罗瓦达到了统计学显著水平（费舍尔精确检验：P = 0.016，小于0.025）。如今，年轻女性已成为瓦隆地区唐氏综合征患者的主要来源。这种与之前模式的变化在1975年突然发生，强烈表明自1974年以来，该地区存在一个或多个与21号染色体减数分裂不分离相关的持续因素，并从1975年起影响唐氏综合征患儿的出生。
