Given a single sperm and a single egg, is there more than one resulting DNA combination they can form given the same human process of combining that genetic material. That is if I have the DNA off an egg sequenced and the DNA off a sperm sequenced, can I programmatically determine the DNA of the child formed by that egg and sperm?

  • $\begingroup$ This is a very-excellent as-well fundamental question $\endgroup$
    – user25568
    Sep 11, 2016 at 15:44
  • $\begingroup$ If there are possibilities of variation... practically impossible to test. However if clones of a single egg and clones of single-sperm, could be prepared, that would be comparable to what you're searching-for; but when told "exactly 1 egg and 1 sperm", there you get only 1 scope to fuse them so you have no way to test other possibilities. In Louis Carroll's term, "Nothing is impossible; but some things are impassible". $\endgroup$
    – user25568
    Sep 11, 2016 at 15:52
  • $\begingroup$ @AlwaysConfused, I'm approaching this from the point of view of calculating a genome from the supplied materials. I listened to a ted talk where a process could - accurately - predict a persons face from only their DNA and my immediate thought was "Could you do the same thing prior to conception". $\endgroup$
    – jjr4826
    Sep 12, 2016 at 14:03

1 Answer 1


Assuming we know the haplotype of the ovule and the haplotype of the spermatozoid, then the genotype of the future egg is perfectly deterministic. This is true to the extend that none of the following rare events occur:

  • mitochondria could be inherited from the father as well
  • mutations in the broad sense (see here for definitions) may occur outside an event of mitosis or meiosis
  • The egg might pick up random sequence floating in the environment

Of course epigenetics elements might vary but this is another discussion.

  • $\begingroup$ There will be any number of combinations that can result during recombination and chromosome separation no? $\endgroup$
    – SciEnt
    Sep 11, 2016 at 19:47
  • 1
    $\begingroup$ Recombination and segregation occurs during meiosis, that is before the formation of the gametes (spermatozoid and ovule). Once we take we consider the haplotype of a specific spermatozoid and the haplotype of a specific ovule, the genotype of the egg is deterministic (except above listed rare events). $\endgroup$
    – Remi.b
    Sep 11, 2016 at 19:55

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