A case of a parthenogenetic 46,XX/46,XY chimera presenting ambiguous genitalia
A case of a parthenogenetic 46,XX/46,XY chimera presenting ambiguous genitalia
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DOI：
10.1038/s10038-020-0748-4
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发表时间：
2020-08-01
影响因子：
3.5
通讯作者：
Taniguchi-Ikeda, Mariko
中科院分区：
文献类型：
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作者：
Kawamura, Rie;Kato, Takema;Taniguchi-Ikeda, Mariko
性染色体不协调嵌合体（XX/XY嵌合体）是一种罕见的人类染色体疾病。我们报告一个男孩，生殖器不明确和尿道下裂，显示46，XY[26]/46，XX[4]在外周血细胞。为了阐明这种嵌合现象发生的机制，我们使用SNP阵列和微卫星分析进行了全基因组基因分型。SNP阵列的B等位基因频率显示三个和五个等位基因组合的混合物，其排除嵌合体但不排除嵌合体，并表明两个胚胎的融合或两个亲本细胞之间共享的亲本单倍型。所有的微卫星标记都显示了一个单一的母系等位基因。从这些结果中，我们得出结论，这个XX/XY嵌合体是由两个不同的父亲等位基因和一个重复的母亲基因组。这种XX/XY嵌合体可能来自二倍体母体细胞，该细胞在受精前通过母体基因组的核内复制形成，与X和Y精子受精。
Sex-chromosome discordant chimerism (XX/XY chimerism) is a rare chromosomal disorder in humans. We report a boy with ambiguous genitalia and hypospadias, showing 46,XY[26]/46,XX[4] in peripheral blood cells. To clarify the mechanism of how this chimerism took place, we carried out whole-genome genotyping using a SNP array and microsatellite analysis. The B-allele frequency of the SNP array showed a mixture of three and five allele combinations, which excluded mosaicism but not chimerism, and suggested the fusion of two embryos or a shared parental haplotype between the two parental cells. All microsatellite markers showed a single maternal allele. From these results, we concluded that this XX/XY chimera is composed of two different paternal alleles and a single duplicated maternal genome. This XX/XY chimera likely arose from a diploid maternal cell that was formed via endoduplication of the maternal genome just before fertilization, being fertilized with both X and Y sperm.