Isodicentric Y chromosomes [idic(Y)] are one of the most common structural abnormalities of the Y chromosome. The prenatal diagnosis of isodicentric Y chromosomes is of vital importance, and the postnatal phenotypes vary widely. Therefore, we present six patients prenatally diagnosed with isodicentric Y chromosomes and review the literature concerning the genotype-phenotype correlations. The clinical materials of six patients were obtained. Cytogenetic and molecular approaches were carried out for these six patients. Isodicentric Y chromosomes were found in all sixpatients. Among them, four patients presented with a mosaic 45,X karyotype, one patient had a 46,XY cell line, and one patient was nonmosaic. Five of these six isodicentric Y chromosomes had a breakpoint in Yq11.2, and the other had a breakpoint in Yp11.3. The molecular analysis demonstrated different duplications and deletions of the Y chromosome. Finally, three patients chose to terminate the pregnancy, two patients gave birth to normal-appearing males, and one patient was lost to follow-up. The incorporation of multiple cytogenetic and molecular techniques would offer a more comprehensive understanding of this structural chromosomal abnormality for genetic counselling.

中文翻译：

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等双着丝粒 Y 染色体的临床、细胞遗传学和分子发现

等双着丝粒 Y 染色体 [idic(Y)] 是 Y 染色体最常见的结构异常之一。等双着丝粒Y染色体的产前诊断至关重要，产后表型差异很大。因此，我们介绍了 6 名产前诊断为等双着丝粒 Y 染色体的患者，并回顾了有关基因型-表型相关性的文献。获得6例患者的临床资料。对这六名患者进行了细胞遗传学和分子学方法。在所有六名患者中均发现了等双着丝粒 Y 染色体。其中，4 例患者呈现镶嵌 45,X 核型，1 例患者具有 46,XY 细胞系，1 例患者为非镶嵌型。这六个等双着丝粒 Y 染色体中有五个在 Yq11.2 中有一个断点，另一个在 Yp11.3 中有一个断点。分子分析显示了 Y 染色体的不同重复和缺失。最终，3名患者选择终止妊娠，2名患者生下外貌正常的男性，1名患者失访。多种细胞遗传学和分子技术的结合将为遗传咨询提供对这种染色体结构异常的更全面的理解。