Fujimoto A, Boelter W D, Sparkes R S, Lin M S, Battersby K
Genetics Division, Los Angeles County/University of Southern California Medical Center 90033.
Am J Med Genet. 1991 Nov 1;41(2):239-45. doi: 10.1002/ajmg.1320410222.
A female twin with short stature, unusual facial appearance, widely spaced nipples, and coarctation of the aorta was found to have a peripheral blood lymphocyte karyotype of 45,X(43%)/46,X,idic(Y)(p11). Her twin brother, also short with similar facial appearance, had the same mosaicism (40% 45,X). Cultured skin fibroblast studies showed discrepant karyotypes of 45,X (100%) in the girl and 45,X (78%)/46,X,idic(Y)(p11) in the boy. The mother and the father had normal chromosomes. Comparison of 27 biochemical markers yielded a likelihood of monozygosity of 0.9977. This report documents the occurrence of discordant phenotypic sex in monozygotic twins, involving gonadal dysgenesis with an abnormal dicentric Y, which presumably occurred de novo, followed by anaphase lag probably before the occurrence of twinning. Unequal distribution of the two resultant cell lines in various tissues of each twin could account for the development of the very different phenotypes, apparently normal boy and Ullrich-Turner girl.
一名身材矮小、面部外观异常、乳头间距宽且患有主动脉缩窄的女性双胞胎，其外周血淋巴细胞核型为45,X(43%)/46,X,idic(Y)(p11)。她的双胞胎兄弟同样身材矮小且面部外观相似，具有相同的嵌合体（40% 45,X）。培养的皮肤成纤维细胞研究显示，女孩的核型为45,X(100%)，男孩的核型为45,X(78%)/46,X,idic(Y)(p11)，二者存在差异。母亲和父亲的染色体正常。对27种生化标志物的比较得出同卵双生的可能性为0.9977。本报告记录了同卵双胞胎中不一致的表型性别情况，涉及性腺发育不全及异常的双着丝粒Y染色体，推测该异常为新发，随后可能在孪生发生之前出现后期延迟。每个双胞胎不同组织中两种产生的细胞系分布不均，可能解释了截然不同的表型发展，即外表正常的男孩和 Ullrich-Turner 女孩。
