The RNASEH2B gene (RNASEH2B stands for "ribonuclease H2 subunit B") is a protein coding gene located on 13q14.3. Several transcript variants encoding different isoforms have been found for this gene.
The protein encoded by "ribonuclease H2 subunit B" is one of the two non-catalytic subunits of RNase H2. RNase H2, an endonuclease consists of a single catalytic subunit (A) and two non-catalytic subunits (B and C). It specifically degrades RNA from RNA:DNA hybrids. It is thought to play a role in DNA replication, possibly by mediating the removal of Okazaki fragment RNA primers from the residual strand during DNA replication. Mediates the excision of single ribonucleotides from DNA:RNA duplexes.
Defects in this gene are a cause of Aicardi-Goutières syndrome type 2 (AGS2). Other mutations have been detected in the TREX1, RNASEH2A, RNASEH2C, SAMHD1, ADAR, or IFIH1 genes (Crow YJ et al. 2015).