NIH

Zebra of the Week: Situs inversus

February 12, 2026

Situs inversus totalis is a congenital laterality disorder in which the thoracic and abdominal organs are positioned as a mirror image of normal visceral anatomy. It may present as an isolated finding or occur within multisystem syndromes, and approximately 5% to 10% of affected individuals have associated congenital heart defects. The condition arises from genetically mediated disruptions in embryologic left–right patterning, with both inherited and sporadic cases reported. Although many individuals remain asymptomatic, recognition is clinically important for accurate diagnostic interpretation, surgical planning, and assessment for coexisting structural abnormalities.

Source:

(Accessed 2026, February 11). NIH Genetic and Rare Diseases Information Center (GARD). Situs inversus. https://rarediseases.info.nih.gov/diseases/4883/situs-inversus