This condition does not have a definite reason or cause for occurring, but there are some suggested beliefs presented about it.
One of the believed causes is that early in the normal development of an embryo, the tube-like structure that becomes the heart, forms a loop toward the left, identifying the left/right axis along which the other organs should be positioned. However, this cause is not completely approved but it is known that at least one gene has been identified to have a role in this process.
Further, it is thought that many factors may be involved in causing Situs Inversus.
Rarely, situs inversus can run in families, but most often it is an isolated and accidental event occurring in an individual for the first time in the family.
3-5% of people with Situs Inversus have any type of functional heart defect, which is higher than the rate of heart defects in the general population, mentioned to be less than 1%.
It is estimated that about 25% of people with Situs Inversus have an underlying condition called Primary Ciliary Dyskinesia (PCD). PCD is caused by a defect in the cilia that impairs their normal movements. Another condition, known as Kartagener's syndrome, consists of Situs Inversus, chronic sinus infections, increased mucous secretions from the lungs, and an increased susceptibility to respiratory infections.
Situs Inversus Totalis has been estimated to occur once in about 6-8,000 births.
Situs Inversus is currently present in 0.01% of the population in the USA or 1 in 10,000.