First of all, let’s assume that it is only the tail involved. A kinked or curly tail in a lizard that uses its limbs for locomotion is likely to have minimal effect on it, if at all. With a snake, depending on the degree of kinking and whether or not there are malformed muscles involved, it may well impede its locomotion. In captivity, this would not be an issue, whereas in the wild it would be.
There is the possibility that the kinked tail is indicative of a more widespread problem.
It could be caused by an environmental influence, in which case it would not be passed on. For example, it may have resulted from insufficient calcium being available to the developing embryo, which would mean that it is odds on there is general skeletal weakness and quite probably other deformities that are not evident from the outside.
If the cause is genetic, then it may be passed on. For example, the animal may be genetically deficient in its ability to utilise calcium. In this case the same probabilities of widespread problems mentioned in the previous paragraph would also apply.
If you have an otherwise healthy animal with a kinked tail, odds are it was environmentally produced and is unlikely to be genetic and to be passed on.