They are classified as vertebrate viruses and have a non-enveloped capsid, which is round with isometric, icosahedral symmetry and has a triangulation number of 3.

The name is derived from Italian anello 'ring', referring to the circular genome of anelloviruses.

The genome is not segmented and contains a single molecule of circular, negative-sense, single-stranded DNA.

[1] They also contain a non-coding region with one to two 80–110 nt sequences that contain high GC content, forming a secondary structure of stems and loops.

[6] ORF2 is thought to either encode a protein with phosphatase activity (TTMVs) or a peptide that suppresses the NF-

[9] It has been shown that there are multiple methods of transmission such as saliva droplets and maternal or sexual routes.