The classification of this family is based on differences in the conserved central region sequence.

The severity of the infection can vary from no effect to devastating and widespread damage to a population.

(+) polarity circRNA molecules (by convention the most abundant strand in vivo) are repeatedly transcribed into oligomeric complementary (−) RNAs.

Such intermediates serve as templates for generating oligomeric (+) RNAs that are cleaved by a host enzyme of the RNase III class.

The termini of the resulting linear monomers are ligated by the host DNA ligase 1 to generate the mature circular viroid RNA.