title: A new case of prenatally diagnosed pentasomy x: review of the literature.
abstract: 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.
authors.affiliation: 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.
authors.forename: Linda Maria Azzurra
authors.initials: LM
authors.lastname: Pirollo
authors.affiliation: Laboratory of Medical Genetics, Polyclinic of Tor Vergata Foundation, Viale Oxford 81, 00133 Rome, Italy.
authors.forename: Leila Baghernajad
authors.initials: LB
authors.lastname: Salehi
authors.affiliation: 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.
authors.forename: Simona
authors.initials: S
authors.lastname: Sarta
authors.affiliation: Laboratory of Medical Genetics, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Cassone
authors.affiliation: 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.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Capogna
authors.affiliation: 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.
authors.forename: Emilio
authors.initials: E
authors.lastname: Piccione
authors.affiliation: Genetics Section, Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Novelli
authors.affiliation: 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.
authors.forename: Adalgisa
authors.initials: A
authors.lastname: Pietropolli