Situs inversus is rarely seen. Why this happens so often in together with PCD is unknown. Genetic aspects PCD is mainly inherited as an autosomal recessive. This means that PCD must be inherited from both parents. The human body is constructed from billions of cells.
All cell contain genetic information which is stored in so-called chromosomes.
All genes are located on a predetermined position on the chromosomes. Each cell has 46 chromosomes, arranged as 23 pairs. All genes are present twice. Only the sperm and female egg contain half of the chromosomes. This is how the properties are transferred from father and mother to the child.