Institute of Medical Genetics, Medical University Vienna, Austria.
Prenat Diagn. 2012 Feb;32(2):173-9. doi: 10.1002/pd.2928.
A higher frequency of twin births in sibships of Klinefelter syndrome patients and also monozygotic or dizygotic twins, themselves being affected by Klinefelter syndrome have been noted repeatedly. To address this issue, we evaluated type and frequency of twinning among Klinefelter fetuses that we had received for autopsy within a 'Prenatal Diagnosis' program.
We performed fetal autopsies, and genetic analyses on DNA extracted from stained histological slides.
Among 41 prenatal diagnoses of a 47, XXY karyotype we observed four twin pairs. One was dizygotic with discordant Klinefelter and Down syndrome. Three twin pairs were monozygotic as concluded from monochorial placentation. In two monozygotic pairs one twin partner was an acardiac monster and in one of these the acardiac twin showed a female gonadal sex and missing Y-chromosomal SRY-sequences as confirmed by polymerase chain reaction.
There is a high rate of twinning and twin reversed arterial perfusion sequence among our Klinefelter fetuses. Forked umbilical cords at the placental insertion site in one case allowed classification as conjoined twins in the sense of a 'funiculopagus'. Anaphase lagging or semidizygosity by second polar body twinning are proposed as explanations for the gonadal sex discordance and the excessive developmental disadvantage in the one acardiac. Problems may arise with regard to non-invasive prenatal diagnosis of aneuploidies in twin pregnancies.
曾有报道称，克氏综合征患者的同胞中双胞胎的出生率较高，而这些双胞胎本身也患有克氏综合征，此外还有同卵或异卵双胞胎。为了解决这个问题，我们评估了我们在“产前诊断”计划中收到的克氏综合征胎儿的孪生类型和频率。
我们对经过染色的组织学切片提取的 DNA 进行了胎儿尸检和遗传分析。
在 41 例产前诊断为 47, XXY 核型的病例中，我们观察到了四对双胞胎。其中一对是异卵双生，且患有克氏综合征和唐氏综合征。另外三对是同卵双生，根据单绒毛膜胎盘得出结论。在两对同卵双胞胎中，一个双胞胎是无心畸形儿，在其中一对中，无心双胞胎的性腺性别为女性，且 Y 染色体上的 SRY 序列缺失，这通过聚合酶链反应得到证实。
我们的克氏综合征胎儿中存在较高的孪生率和双胎反向动脉灌注序列。在一例中，分叉脐带在胎盘插入部位允许按照“联体双胎”的意义进行分类。后期滞后或第二次极体二倍体分裂被认为是导致性腺性别不一致和一个无心畸形儿发育过度不良的原因。在双胞胎妊娠的非侵入性产前诊断中可能会出现问题。
