Vascular abnormalities:
Interrupted inferior vena cava,
Bilateral superior or inferior venae cavae
Intrahepatic interruption of the inferior vena cava with connection to the azygos or hemiazygos veins
Aberrant portal veins. Bronchial tree and lungs
Pathophysiology in the bronchial tree can be observed by radiography. Under normal development, the bronchial tree consists of two main bronchi that are anatomically different:

Hyparterial bronchus (below the pulmonary artery): supplies blood to the bi-lobed left lung
Eparterial bronchus (adjacent to the artery): supplies blood to the tri-lobed right lungIn situs ambiguus, there is a duplication of either the hyparterial or eparterial bronchus. These features are not associated with any significant clinical complications. Mechanisms leading to bronchial duplication are not thoroughly understood. In pulmonary valve stenosis, there is a reduction in blood flow to the lungs due to an obstruction of the heart at the pulmonic valve. This contributes to cyanosis and pulmonary hypertension. Diagnosis
For proper diagnosis of situs ambiguus, cardiac and non-cardiac features must be evaluated. Diagnostic criteria for atrial isomerism includes observation of symmetry of thoracic visceral organs upon echocardiogram, arrhythmia upon electrocardiogram, and chest x-ray for confirmation of the hearts location across the left-right axis. Additional radiographic and cross-sectional imaging may be obtained to evaluate both cardiac and non-cardiac manifestations of situs ambiguus. In addition, a series of gastrointestinal tests can be conducted for observation of intestinal malrotation, as well as a scan of the liver and spleen for biliary function.
FISH (Fluorescent in situ hybridization) is used to confirm the diagnosis by distinguishing idic(15) from other supernumerary marker chromosomes. Array CGH can be used to determine the gene content and magnitude of copy number variation so that the clinical picture can be foreseen. Interstitial duplications of chromosome 15 can be more difficult to detect on a routine chromosome analysis but are clearly identifiable using a 15q FISH study. Families should always discuss the results of chromosome and FISH studies with a genetic counselor or other genetics professionals to ensure accurate interpretation. Screening
In general, idic(15) occurs de novo but the parents must be karyotyped to make sure it is not inherited, mostly because this will affect the course of genetic counseling given to the family. If the abnormality is found prenatally and one of the parents harbour the marker, the child has a chance of not carrying the mutation. Further tests should however be done to prove the marker has not been rearranged while being inherited. This information is also necessary for counseling of future pregnancies. Each family is unique and should therefore be handled individually. Management
At the present time, there is no specific treatment that can undo any chromosomal abnormality, nor the genetic pattern seen in people with idic(15). The extra chromosomal material in those affected was present at or shortly after conception, and its effects on brain development began taking place long before the child was born. Therapies are available to help address many of the symptoms associated with idic(15).