Korsun P, Bals-Pratsch M, Ortmann O, Markus S, Germer U
Klinik für Frauenheilkunde und Geburtshilfe der Universität Regensburg am Caritas-Krankenhaus St. Josef, Regensburg.
Profertilita, Zentrum für Fruchtbarkeitsmedizin, Regensburg.
Geburtshilfe Frauenheilkd. 2016 Jun;76(6):727-730. doi: 10.1055/s-0042-101024.
Monochorionic twins are usually monozygotic and thus usually have the same sex. A case of monochorionic diamniotic twins following IVF/ICSI and laser treatment of the zona pellucida ("assisted hatching") is presented in which partial embryo amalgamation appears to have occurred. Discordant sex between the twins was suspected on detailed antenatal ultrasound at 13 + 3 weeks gestation and was confirmed on subsequent examinations. The sexual phenotype at birth was female for one twin and male for the other. Placental histology confirmed the monochorionic, diamniotic situation. Cytogenetic analysis of both twins was carried out postpartum on various tissues. On karyotyping of blood lymphocytes the male and female twins each had one mosaic of male and female cells. Oral mucosal cells showed normal male and female karyotypes respectively. Analysis of urothelium showed a normal result for the male infant, and a weak gonosomal mosaic with an XX and XY constellation for the female infant. At least for blood lymphocytes, a diagnosis of chimerism was proven.
单绒毛膜双胎通常是单卵双胎，因此通常性别相同。本文报告了一例体外受精/卵胞浆内单精子注射（IVF/ICSI）及透明带激光治疗（“辅助孵化”）后的单绒毛膜双羊膜囊双胎病例，其中似乎发生了部分胚胎融合。在妊娠13⁺3周进行详细的产前超声检查时怀疑双胎性别不一致，随后的检查证实了这一点。出生时一个双胎的性表型为女性，另一个为男性。胎盘组织学证实为单绒毛膜双羊膜囊情况。产后对两个双胎的各种组织进行了细胞遗传学分析。对血液淋巴细胞进行核型分析时，男性和女性双胎均各有一组男性和女性细胞的嵌合体。口腔黏膜细胞分别显示正常的男性和女性核型。对尿路上皮的分析显示男婴结果正常，女婴为XX和XY组合的弱性染色体嵌合体。至少对于血液淋巴细胞，证实了嵌合体的诊断。
