Pentasomy 49,XXXXY diagnosed in utero: case report and systematic review of antenatal findings.

OBJECTIVES Pentasomy 49,XXXXY is a rare sex chromosome polysomy usually diagnosed postnatally by the combina- tion of mental retardation, facial dysmorphism, and genital, cardiac and skeletal malformations. Prenatal detection of 49,XXXXY is unusual and may be incidental due to non-specific ultrasound (US) findings. We report a case of 49,XXXXY diagnosed prenatally and present a literature review of the few prenatally diagnosed cases. METHODS We searched the PubMed electronic database without year and language restriction, using the keywords 'Prenatal', 'Diagnosis', and '49,XXXY', performing a systematic review. RESULTS We report a 35-year-old patient with normal first-trimester US but increased combined risk for trisomies 18 and 13. Amniocentesis at 16 weeks of gestation revealed a 49,XXXXY karyotype. Pregnancy was terminated at 19 weeks' gestation, and a male fetus with facial dysmorphism and hypospadia was delivered. A total of 12 articles were identified in the systematic review. All were case reports and dated from 1980 until 2008. The mean maternal age was 34.8 years (range 30-41). The most common prenatal US feature was cystic hygroma, present in 5 cases. Hypogenitalism was the most common macroscopic clinical feature identified after pathology examination in 7 cases. In 2 cases, there was an increase in first-trimester combined risk for trisomy 21. CONCLUSIONS Pentasomy 49,XXXXY is associated with a variety of non-specific US findings, of which cystic hygroma was the commonest. No specific sequence of findings could be identified in this review.