Pirollo Linda Maria Azzurra, Salehi Leila Baghernajad, Sarta Simona, Cassone Marco, Capogna Maria Vittoria, Piccione Emilio, Novelli Giuseppe, Pietropolli Adalgisa
Section of Gynecology and Obstetrics, Academic Department of Biomedicine and Prevention and Clinical Department of Surgery, Tor Vergata University Hospital, Viale Oxford 81, 00133 Rome, Italy.
Laboratory of Medical Genetics, Polyclinic of Tor Vergata Foundation, Viale Oxford 81, 00133 Rome, Italy.
Case Rep Obstet Gynecol. 2015;2015:935202. doi: 10.1155/2015/935202. Epub 2015 Jan 29.
Pentasomy X is a rare chromosomal abnormality probably due to a nondisjunction during the meiosis. Only four cases prenatally diagnosed were described until now. Our case is the fifth one prenatally diagnosed at 20 weeks of gestational age in a 39-years-old woman. She underwent invasive prenatal diagnosis for her advanced maternal age without any other known risk factor. Amniocentesis performed at 17 weeks showed a female 49, XXXXX karyotype. The ultrasonographic examination revealed nonspecific signs of a mild early fetal growth retardation and no significant increased nuchal fold. The fetal autopsy and the X-ray excluded major malformations. Prenatal diagnosis is often difficult due to the lack of indicative ultrasonographic findings and the rarity of described cases. The influence of the mother's age on the occurrence of penta-X syndrome has not been determined. Considering the lack of correlation between advanced maternal age and increased risk for pentasomy X, as well as the absence of typical echographic signs, evaluation of the inclusion of a noninvasive prenatal test (NIPT) that expands clinical coverage to include the X and Y chromosomes in routine prenatal diagnosis should be considered as well as three-dimensional ultrasound to detect any helpful indicative prognostic signs.
X染色体五体性是一种罕见的染色体异常，可能是由于减数分裂期间的不分离所致。到目前为止，仅描述了4例产前诊断的病例。我们的病例是第5例，在一名39岁女性妊娠20周时产前诊断出来。由于她高龄产妇且无其他已知危险因素，她接受了侵入性产前诊断。17周时进行的羊膜穿刺术显示胎儿核型为女性49,XXXXX。超声检查显示有轻度早期胎儿生长迟缓的非特异性体征，且颈部褶皱无明显增厚。胎儿尸检和X线检查排除了重大畸形。由于缺乏指示性超声检查结果且所描述的病例罕见，产前诊断往往很困难。母亲年龄对X染色体五体综合征发生的影响尚未确定。考虑到高龄产妇与X染色体五体性风险增加之间缺乏相关性，以及缺乏典型的超声体征，应考虑评估在常规产前诊断中纳入扩展临床覆盖范围以包括X和Y染色体的无创产前检测（NIPT）以及三维超声，以检测任何有用的指示性预后体征。
