Hypermethylation of the 7-(mono)methylguanosine (m(7)G) cap structure at the 2' position of the guanosine residue to convert a mono-methylated cap to a 2,2,7-trimethylguanosine cap structure. This type of cap modification occurs on small nuclear RNAs (snRNAs) and small nucleolar RNAs (snoRNAs) and is dependent on prior guanine-N7 methylation. (Gene Ontology, GO_0036261)
7 genes participating in the 7-methylguanosine cap hypermethylation biological process from the curated GO Biological Process Annotations 2025 dataset.
