Rare case of massive congenital bilateral chylothorax in a hydropic fetus with true mosaicism 47,XXX/46,XX

Abstract

Fetal congenital chylothorax is a rare condition that occurs sporadically or can be associated with abnormal karyotype or structural chromosomal anomalies. We report a unique case of fetal congenital bilateral chylothorax associated with mosaicism 47,XXX/46,XX. A female fetus affected by massive bilateral hydrothorax and ascites was diagnosed at 34(+1) weeks of gestation. Previous ultrasonographic exams were completely normal. Immune causes of hydrops were excluded. Elective cesarean section was performed soon after bilateral thoracocentesis. The analysis of drained pleural fluid revealed its lymphatic nature. The fetal karyotyping, performed on chorionic villi at the 11th week, had shown mosaicism 47,XXX/46,XX, later confirmed in the newborn's blood. We hypothesized that chylothorax may be part of the phenotypic spectrum of 47 XXX karyotype and we suggest an ultrasound follow-up of the fetus at closer intervals than the routine timing for this condition, even if it is not usually characterized by severe phenotypic features.

Fetal Hydrops Associated With 47,XXX: A Case Report and Literature Review

“…The results of the review are shown in Table 1. In our review, we identified three cases of fetal hydrops associated with 47,XXX [7][8][9]. In cases 2 and 3, chromosome testing was conducted owing to an advanced maternal age, and a 47,XXX karyotype was found.…”

Subtle phenotypic effects of mosaic trisomy X in monozygotic twins with Prader-Willi syndrome: case report and review of literature

“…Comparing to complete 47, XXX, clinical symptoms of individuals with 46, XX/47, XXX mosaicism are less severe and expectations of their outcomes are better[5]. Still, there are reports on severe symptoms of 46, XX/47, XXX mosaicism including autoimmune myelo brosis, congenital chylothorax and azoospermia[18][19][20].…”