Chromosome translocations are a type of abnormality in which the chromosomes are arranged in an unusual manner. They are caused when a segment of chromosome breaks and the fragmented pieces get reattached to a new locus on the same chromosome or to a different, non-homologous chromosome. 

Chromosome translocations typically take place during meiosis, when a double strand of chromosome breaks and the resulting DNA fragments join to different areas on the same or different chromosome.