Manning C H, Goodman H O
Hum Genet. 1981;59(2):101-3. doi: 10.1007/BF00293054.
The number of 21 chromosomes of 15 individuals with Down's syndrome and their parents were examined in an attempt to determine the parental origin of the extra number 21 chromosome and the stage of meiosis at which nondisjunction occurred. Chromosomes were stained with quinacrine hydrochloride and photographed; serial prints were made ranging from underexposed to overexposed. Twelve of the 15 families (80%) were informative: nondisjunction occurred in maternal meiosis I in eight (66.7%) families, in paternal meiosis I in two (16.7%) families, and in paternal meiosis II in two (16.7%) families. The production of serial exposures of chromosomes at the time of printing proved to be a valuable method of enhancing slight differences in short arm and satellite structure of the number 21 chromosomes and thereby increasing the number of informative families.
对15名唐氏综合征患者及其父母的21号染色体数量进行了检查，以确定额外的21号染色体的亲本来源以及发生不分离的减数分裂阶段。染色体用盐酸喹吖因染色并拍照；制作了从曝光不足到曝光过度的系列照片。15个家庭中有12个（80%）提供了有用信息：8个（66.7%）家庭的不分离发生在母本减数分裂I期，2个（16.7%）家庭的不分离发生在父本减数分裂I期，2个（16.7%）家庭的不分离发生在父本减数分裂II期。在冲印时制作染色体的系列曝光照片被证明是一种有价值的方法，可增强21号染色体短臂和随体结构的细微差异，从而增加提供有用信息的家庭数量。
