has_sequence_attribute aneusomic chromosome A complete chromosome that has been abnormally duplicated, or the absense of a chromosome that has been lost, typically as the result of a non-disjunction event or unbalanced translocation Large sequence features gained in a genome are considered to be sequence alterations (akin to insertions), including aneusomic chromosome segments gained through unbalanced translocation events, entrie aneusomic chromosomes gained through a non-disjunction event during replication, or extrachromosomal replicons that become part of the heritable gneme of a cell or organism. Similarly, large sequence features lost from genome are akin to deletions and therefore also considered sequence alterations. This includes the loss of chromosomal segments through unbalanced translocation events, and the loss of entire chromosomes through a non-disjunction event during replication. complete aneusomic chromosome aneusomic chromosome sequence_alteration exploratory term