A de novo homozygous missense mutation of the GUSB gene leads to mucopolysaccharidosis type VII identification in a family with twice adverse pregnancy outcomes due to non-immune hydrops fetalis

Runxuan Du; Haishen Tian; Bingyi Zhao; Xuedong Shi; Yanmei Sun; Bo Qiu; Yali Li

doi:10.1016/j.ymgmr.2023.101033

A de novo homozygous missense mutation of the GUSB gene leads to mucopolysaccharidosis type VII identification in a family with twice adverse pregnancy outcomes due to non-immune hydrops fetalis

Mol Genet Metab Rep. 2023 Dec 6:38:101033. doi: 10.1016/j.ymgmr.2023.101033. eCollection 2024 Mar.

Authors

Runxuan Du¹, Haishen Tian¹, Bingyi Zhao¹, Xuedong Shi¹, Yanmei Sun¹, Bo Qiu², Yali Li¹

Affiliations

¹ Department of Reproduction and Genetics, Hebei General Hospital, Hebei Provincial, Shijiazhuang, China.
² Department of pharmacy, Hebei General Hospital, Hebei Provincial, Shijiazhuang, China.

Abstract

Non-immune hydrops fetalis (NIHF) is a common and severe manifestation of many genetic disorders. The ultrasound is an ideal method for diagnosing hydrops fetalis during pregnancy. Since most NIHFs do not have an identifiable cause, determining the underlying etiology remains a challenge for prenatal counseling. Due to advancements in exome sequencing, the diagnostic rates of NIHF have recently increased. As reported here, DNA was extracted from the amniotic fluid of a pregnant woman who was prenatally diagnosed with a NIHF type of unclear origin. Amniocentesis sampling demonstrated a normal female karyotype and copy number variation(CNVs) without alterations. Tri-whole exome sequencing (WES) was conducted to identify possible causative variants. In the fetus, a de novo genetic mutation was identified as a homozygous form. The mutation was located on the glucuronidase beta (GUSB) gene: NM_000181.3: c.1324G > A; p. Ala442Thr; Chr7:65439349, which leads to mucopolysaccharidosis type VII. This mutation was inherited from the parents and was first reported to be related to NIHF. We conclude that the use of WES is beneficial for NIHF cases whose prognosis has not been explained by standard genetic testing.

Keywords: Case report; GUSB gene; Mucopolysaccharidosis type VII; Non-immune hydrops fetalis; Whole exome sequencing.

Publication types

Case Reports