A fetus of partial urorectal septum malformation sequence characterized by complete septate uterus: A case report

Urorectal septum malformation sequence (URSMS) is an extremely uncommon anomaly characterized by imperforate anus accompanied by multiple genitourinary malformations. Here, we report a case of URSMS identified by the autopsy and classified into partial URSMS. Prenatal diagnosis is challenging for clinicians due to the difficulty of early identification of URSMS and the relative lack of specific features in ultrasound. We intend to share our experiences.

One fetus was indicated abdominal cystic structure, abdominal effusion and right renal pelvis separation (7 mm) by ultrasound at 28 + 1 week's gestation. After the pregnancy was terminated, the fetal tissues were performed to be tested by autopsy, copy number variation sequencing and whole exon sequencing.

Based on the clinical characteristics, ultrasound, autopsy, and genetic test findings, the fetus was diagnosed with URSMS.

After genetic counseling, the couple opted to terminate her pregnancy.

The copy number variation results of the fetus showed a 0.48-MB duplication fragment of uncertain significance on chromosome 8p23.3, while the whole-exome sequencing revealed a SAL-LIKE 1 gene mutation. The autopsy of the fetus showed imperforate anusa, the abdominal cyst was further confirmed with complete septate uterus and the lower urethra and vagina converge formed a lumen.

Individuals with URSMS during the fetal period might be misdiagnosed due to atypical features of URSMS. Once structural abnormalities especially cystic mass of the futuses in the lower abdomen, URSMS should be considered.