The genetic relationship between a mother cat and her sons is called inbreeding. There are certain risks associated with inbreeding, as similarities in genetic material can increase the risk of genetic defects and genetic diseases.
However, inbreeding does not necessarily result in all offspring being unable to survive. If neither mother nor son have underlying genetic problems, there is still a chance that their offspring will survive healthy. However, to avoid the risk of genetic diseases and defects, outbreeding, i.e. breeding with other unrelated cats, is recommended. This can increase the genetic diversity of the population and reduce the occurrence of genetic problems.