Heterotaxy ('heter' meaning 'other' and 'taxy' meaning 'arrangement'), or situs ambiguus, is a developmental condition characterized by randomization of the placement of visceral organs, including the heart, lungs, liver, spleen, and stomach. The organs are oriented randomly with ... Heterotaxy ('heter' meaning 'other' and 'taxy' meaning 'arrangement'), or situs ambiguus, is a developmental condition characterized by randomization of the placement of visceral organs, including the heart, lungs, liver, spleen, and stomach. The organs are oriented randomly with respect to the left-right axis and with respect to one another (Srivastava, 1997). Heterotaxy is a clinically and genetically heterogeneous disorder. For a discussion of the genetic heterogeneity of visceral heterotaxy, see HTX1 (306955).
In the patient reported by Peeters et al. (2001), routine ultrasound examination at gestational age 28 weeks had shown atrioventricular septal defect and abdominal situs inversus. Chromosome analysis after amniocentesis demonstrated a balanced translocation with breakpoints at 6q21 ... In the patient reported by Peeters et al. (2001), routine ultrasound examination at gestational age 28 weeks had shown atrioventricular septal defect and abdominal situs inversus. Chromosome analysis after amniocentesis demonstrated a balanced translocation with breakpoints at 6q21 and 20p13. The karyotypes of the parents were normal. Postnatally, the patient was found to have mesocardia, atrioventricular septal defect with monoatrium (large atrial septal defect type I), and left atrial isomerism. The abdominal aorta was on the right side. The inferior vena cava was on the left side. The liver was on the left, the stomach and spleen on the right, and intestinal malrotation was present.