intrachromosomally

intrachromosomal +‎ -ly = intra- +‎ chromosome +‎ -ally

intrachromosomally (not comparable)

1. Within a chromosome.
   • 2015 September 9, Natasha M. Glover et al., “Small-scale gene duplications played a major role in the recent evolution of wheat chromosome 3B”, in Genome Biology‎, volume 16, →DOI:

     Recombination as well as gene density increases with relative distance from the centromere, and intrachromosomally duplicated genes are found more frequently at the distal regions of the chromosome.

• interchromosomally