Inamdar Arati A, Diamond Michael, Shertz Wendy
Department of Pathology, Monmouth Medical Center, Long Branch, New Jersey.
Pediatr Dev Pathol. 2020 Sep-Oct;23(5):392-398. doi: 10.1177/1093526620908459. Epub 2020 May 4.
The occurrence of monochorionic diamniotic twins with sex discordance is a very rare phenomenon. We present a case of spontaneously conceived gender-discordant monochorionic diamniotic twins born to a 23-year-old female, both twins demonstrating similar blood karyotype 45,X/46,X, idic(Y) and a novel 99 kb mutation at 3p24.3 involving exons 15-16 of transcript NM_001134381.1 of the () gene. The male twin showed no anatomic abnormalities and pelvic ultrasound revealed descended gonads. The female twin had a horseshoe-shaped kidney, normal uterus, and intra-abdominal gonads. The blood karyotype and microarray studies revealed similar distribution of X and isodicentric Y chromosome along with a novel genetic mutation which has not been previously reported. Our case findings not only report Turner syndrome mosaicism with a novel genetic mutation but also stress the importance of clinical follow-up of twins in order to evaluate the functional abnormalities associated with isodicentric Y chromosomes including germ cell tumors.
单绒毛膜双羊膜囊异性双胞胎的发生是一种非常罕见的现象。我们报告一例23岁女性自然受孕的性别不一致的单绒毛膜双羊膜囊双胞胎病例，两个双胞胎均显示相似的血液核型45,X/46,X,idic(Y)，以及3p24.3处一个涉及()基因转录本NM_001134381.1外显子15 - 16的99 kb新突变。男性双胞胎未显示解剖学异常，盆腔超声显示性腺已降入阴囊。女性双胞胎有马蹄形肾、正常子宫和腹腔内性腺。血液核型和微阵列研究显示X和等臂双着丝粒Y染色体的分布相似，同时还有一个先前未报道的新基因突变。我们的病例发现不仅报告了伴有新基因突变的特纳综合征嵌合体，还强调了对双胞胎进行临床随访以评估与等臂双着丝粒Y染色体相关的功能异常（包括生殖细胞肿瘤）的重要性。
