chromosome ring

https://doi.org/10.1351/goldbook.10526
Abnormal chromosome in which both ends have been lost and the two broken ends have reunited to form a ring-shaped structure.
Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 736 [Terms] [Paper]