Prenatal Ultrasound Observations and Postnatal Manifestations Linked to PIGW Variants.

Objective: We present a case of a fetus from a Chinese family. Ultrasound examination during the second trimester revealed increased fetal abdominal circumference, enlarged liver, tent-like mouth, frequent tongue movement, micro-fist-like hands in fixed positions, hydronephrosis with bilateral ectopic ureteral openings, scrotal echoes visible in the external genitalia, no significant penile echo, and polyhydramnios. To determine the genetic cause of this fetus, we performed a prenatal diagnosis.

Method: Trio whole-exome sequencing (trio-WES) was performed on the fetus and his parents to identify the genetic cause, and subsequent verification was performed by Sanger sequencing.

Results: A compound heterozygous variation in the PIGW gene was identified by trio-WES. The frameshift variant (NM_178517.5: c.617_620del, p.Val206fs) was inherited from the unaffected mother, and the novel missense variant (NM_178517.5: c.842T>G, p.Leu281Arg) was inherited from the unaffected father.

Conclusion: To our knowledge, the current prenatal reports on PIGW remain extremely limited. Our report expands the prenatal phenotype associated with this gene, such as the first detection of abnormal fetal activities in utero, including frequent tongue movements and fixed hand positions.