Ergun-Longmire Berrin, Vinci Giovanna, Alonso Lita, Matthew Susan, Tansil Susan, Lin-Su Karen, McElreavey Ken, New Maria I
Department of Pediatrics, The New York Presbyterian Hospital-Weill Medical College of Cornell University, New York, NY, USA.
J Pediatr Endocrinol Metab. 2005 Aug;18(8):739-48. doi: 10.1515/jpem.2005.18.8.739.
The main factor influencing the sex determination of an embryo is the genetic sex determined by the presence or absence of the Y chromosome. However, some individuals carry a Y chromosome but are phenotypically female (46,XY females) or have a female karyotype but are phenotypically male (46,XX males). 46,XX maleness is a rare sex reversal syndrome affecting 1 in 20,000 newborn males. Molecular analysis of sex-reversed patients led to the discovery of the SRY gene (sex-determining region on Y). The presence of SRY causes the bipotential gonad to develop into a testis. The majority of 46, SRY-positive XX males have normal genitalia; in contrast SRY-negative XX males usually have genital ambiguity. A small number of SRY-positive XX males also present with ambiguous genitalia. Phenotypic variability observed in 46,XX sex reversed patients cannot be explained only by the presence or absence of SRY despite the fact that SRY is considered to be the major regulatory factor for testis determination. There must be some other genes either in the Y or other autosomal chromosomes involved in the definition of phenotype. In this article, we evaluate four patients with 46,XX male syndrome with various phenotypes. Two of these cases are among the first reported to be diagnosed prenatally.
影响胚胎性别决定的主要因素是由Y染色体的存在与否所决定的遗传性别。然而，一些个体虽携带Y染色体但表型为女性（46,XY女性），或具有女性核型但表型为男性（46,XX男性）。46,XX男性化是一种罕见的性反转综合征，在每20000例新生男婴中出现1例。对性反转患者的分子分析导致了SRY基因（Y染色体上的性别决定区域）的发现。SRY的存在会使双潜能性腺发育为睾丸。大多数46, SRY阳性的XX男性生殖器正常；相比之下，SRY阴性的XX男性通常存在生殖器模糊不清的情况。少数SRY阳性的XX男性也表现出生殖器模糊不清。尽管SRY被认为是睾丸决定的主要调节因子，但在46,XX性反转患者中观察到的表型变异性不能仅用SRY的存在与否来解释。在Y染色体或其他常染色体上必定存在一些其他基因参与表型的定义。在本文中，我们评估了4例具有不同表型的46,XX男性综合征患者。其中2例是最早报道的产前诊断病例。
