Terminology for Variation in Chromosome Numbers

Term Explanation
Aneuploidy 2n ± x chromosomes
    monosomy 2n - 1
    trisomy 2n + 1
    tetrasomy, pentasomy, etc. 2n + 2, 2n + 3, etc.
Polyploidy 3n, 4n, 5n….
    triploidy 3n
    tetraploidy, pentaploidy, etc 4n, 5n, etc.
        autopolyploidy Multiples of the same genome
        allopolyploidy Multiples of different genomes