Non-immune hydrops fetalis in Saudi family secondary to a rare genetic cause

Abstract

Background: Non-immune hydrops fetalis (NIHF) is the abnormal accumulation of serous fluid in more than two fetal or neonatal interstitial spaces due to non-immune causes. It is a serious condition that requires extensive medical care as it indicates severe fetal compromise. Severe anemia, infections, heart or lung defects, and liver disease are all possible causes. Less common causes of NIHF include single gene defects and chromosomal abnormalities. Case Presentation: We report a 2-month-old girl born at 32 weeks of gestation and found to have polyhydramnios and massive congenital ascites. Whole exome sequencing (WES) identified a biallelic pathogenic variant c.617G>A p. (Cys206Tyr) in the thrombospondin 1 domain-containing protein 1 (THSD1) gene. She was misdiagnosed to have ascites secondary to liver dysfunction. Conclusion: Rare causes of fetal hydrops like THSD1 mutation need to be excluded in cases of recurrent non-immune hydrops with no obvious etiology.