hexasome

Probably formed by the combination of hexa- +‎ -some, after the earlier hexasomic (1922) and hexasomy (1939).

hexasome (plural hexasomes)

1. Any one of six homologous chromosomes in an aneuploid complement.
   • 2003, Jesper Q. Svejstrup, “Histones Face the FACT” in Science (New Series) CCCI, № 5,636 (22nd August 2003), page 1,053:

     FACT enables the displacement of the histone H2A/H2B dimer from the nucleosome octamer, leaving a “hexasome” on the DNA.

• hexasomic
• hexasomy