Can once be used with over-represented?

Question

The sentence I'm thinking about is:

Trisomy is an aneuploidy (numerical chromosomal mutation) in which a chromosome is over-represented once.

Background:

Organisms like human beings have a pair of each type of chromosome; two Chr-1 two Chr-2 ..... two Chr-23; it has a pair of 23 chromosomes. So they are called diploids(2n, n=total types of chromosome, 23 in humans) (di means two). Now, Trisomy is a condition in which a diploid organism happens to have an extra copy of a particular chromosome (2n + 1), i.e. they have three copies of that chromosome and I'm trying to bring out the presence of a single extra copy of chromosome in the definition.

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Edit:

I want to use a similar phrase to define tetrasomy too in which there are four copies of a particular chromosome- ....over-represented twice.

Can once be used with over-represented/under-represented in this way? If not how can it be framed?

Answer 1

While certainly not a common construct, over-represented once seems to make sense and be grammatical in your example. What sounds awkward to me is that once typically has an association with time, but in the example the association is with quantity. That doesn't make its usage here incorrect, however. It is perfectly fine to say, "It only replicated itself once." There is little difference between that usage and the geeky phrase, "over-represented once".

More common English might word it as, "... in which a chromosome occurs one time too many."