Pro-Basketball Players Are Not Mutants

Do very tall people like pro-basketball players have special genetics mutations that make them really tall?

Or, do they just have a nearly complete collection of the common genetic variants that tend to make people taller as a matter of more or less random chance?

The answer is the latter. 

All of the height of a very tall pro-basketball player whose genome was examined (citing this study) can be explained by having an above average (at the 4.2 standard deviation level, which is 198 more than the average) proportion of the 2,910 known common height related genes that favor greater height (technically speaking, this is actually 198 more than the average proportion of 2,910 "single nucleotide polymorphisms" a.k.a. SNPs, rather than "genes" in the narrow technical sense of that word).

These individuals just happen to be at the extreme end of the bell curve for height.