Willis M J H, Bird L M, Dell'aquilla M, Jones M C
Department of Pediatrics, University of California, San Diego, USA.
Prenat Diagn. 2006 Feb;26(2):134-7. doi: 10.1002/pd.1352.
The karyotype 46,X,isodicentric Y has rarely been reported in the context of prenatal diagnosis. The literature is replete with descriptions of individuals with 46,X,isodicentric Y/45,X mosaicism, presenting with a spectrum of phenotypes. The postnatal phenotype is believed to depend on the extent of mosaicism in the gonads or other affected tissues. The purpose of this article is to delineate the natural history of this chromosomal abnormality when identified in the context of prenatal diagnosis.
We identified a 45,X/46,X,idicY karyotype in the structurally normal male fetus of a woman presenting with an abnormal triple screen. Four other prenatally ascertained cases were found in our files as well as ten in the medical literature.
Of the 15 cases presented here, 11 (73%) were reported as phenotypically normal males, 1 was found to have an epididymal cyst, and 1 had normal male genitalia, but was also found to have a cardiovascular defect. One out of 15 (7%) was found to have female genitalia and was therefore confirmed to have Turner syndrome. In one case, the outcome was not reported.
An individual diagnosed prenatally with idic(Y) may in many cases be a normal male, similar to the outcome for prenatally diagnosed 45,X/46,XY.
核型46,X,等臂Y在产前诊断中鲜有报道。文献中充斥着对46,X,等臂Y/45,X嵌合体个体的描述，这些个体表现出一系列的表型。产后表型被认为取决于性腺或其他受影响组织中嵌合体的程度。本文的目的是描述在产前诊断中发现的这种染色体异常的自然病史。
我们在一名三联筛查异常的女性的结构正常的男性胎儿中鉴定出45,X/46,X,idicY核型。在我们的档案中还发现了其他4例产前确诊的病例，医学文献中也有10例。
在本文报道的15例病例中，11例（73%）报告为表型正常男性，1例发现有附睾囊肿，1例有正常男性生殖器，但也发现有心血管缺陷。15例中有1例（7%）有女性生殖器，因此确诊为特纳综合征。有1例未报告结局。
产前诊断为idic(Y)的个体在很多情况下可能是正常男性，这与产前诊断为45,X/46,XY的结局相似。
