Situs Inversus- A Not-so-Uncommon Entity

Abstract

Positioning of the abdominal and thoracic organs can be described under three headings of situs solitus (normal body asymmetry), heterotaxy, and situs inversus (mirror image orientation of abdominal and thoracic organs). Heterotaxy and situs inversus can be explained by genetic mutations of genes responsible for body laterality during the period of embryological development. Situs inversus is a condition identified by mirror image orientation of abdominal and the thoracic organs. It affects almost 1 in every 8000 to 25,000 live births and approximately 20–25% are associated with Kartagener syndrome [1–3], which is generally inherited as an autosomal recessive disorder [4]. Situs inversus with levocardia is rarer than situs inversus with dextrocardia. Situs inversus with dextrocardia generally remains asymptomatic throughout life and may seldomly present due to volvulus, duodenal atresias, diaphragmatic hernia, primary biliary atresia or even acute appendicitis [1]. While situs inversus with levocardia presents with congenital heart defects (generally transposition of great vessels) in a frequency more than that for normal population. Thus very few patients survive past 5 years of age.