SITUS inversus totalis diagnosed prenatally plus DNAH11 variants highlights why imaging and genetic testing guide counseling today.
Situs inversus totalis (SIT) is a rare congenital laterality condition marked by complete mirror-image transposition of the thoracoabdominal organs. While SIT is often compatible with a favorable prognosis, prenatal diagnosis can raise immediate questions about associated structural anomalies and ciliopathy-related disorders that meaningfully affect counseling.
In this case report and literature-informed discussion, clinicians identified SIT during routine prenatal ultrasound, then used fetal echocardiography to further characterize anatomy and evaluate for cardiac malformations. Beyond confirming laterality findings, the workup focused on clarifying whether SIT appeared isolated or part of a broader genetic or syndromic picture, which is central to risk assessment and anticipatory guidance.
Situs Inversus Totalis: Prenatal Diagnosis and Counseling
Chromosomal microarray (CMA) testing was unremarkable, but whole exome sequencing (WES) revealed compound heterozygous pathogenic variants in DNAH11, with one variant inherited from each parent. Importantly, no other structural malformations were detected on imaging. These results created a nuanced counseling scenario: isolated SIT is often non-lethal and may not predict poor outcome, yet DNAH11 variants can suggest an underlying ciliary motility disorder.
The authors emphasize that the prenatal pathway for SIT benefits from a multidisciplinary team approach that integrates detailed imaging with comprehensive genetic testing. In practice, fetal echocardiography helps exclude major cardiac defects, while WES can clarify ciliopathy risk when laterality findings prompt concern for shared genetic etiologies.
Following comprehensive counseling, the family elected to terminate the pregnancy at 35 weeks’ gestation. No postnatal examination was performed. The case highlights how genetic findings, even in the absence of additional malformations, may influence parental decision-making and underscores the importance of clear communication around prognostic uncertainty, potential respiratory implications, and postnatal follow-up considerations when a ciliopathy is suspected, including primary ciliary dyskinesia.
Reference: Du X et al. Situs Inversus Totalis: A Case Report and Literature Review. Clin Case Rep. 2026;14(2):e71941.
