RNASEH2A Gene

The RNASEH2A gene (RNASEH2A stands for "Ribonuclease H2 Subunit A") is a protein coding gene located at 19p13.13. The encoded protein of "Ribonuclease H2 Subunit A" is the catalytic subunit of RNase H2. The heterotrimeric type II ribonuclease H enzyme (RNaseH2), an endonuclease, consists of a single catalytic subunit (A) and two noncatalytic subunits (B and C).

The enzyme 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 excision of single ribonucleotides from DNA:RNA duplexes.

Mutations in this gene cause Aicardi-Goutières syndrome 4 (AGS), an autosomal recessively inherited neurological disorder characterized by progressive microcephaly and psychomotor retardation, intracranial calcifications, increased interferon-alpha levels, and white blood cells in the cerebrospinal fluid.Other mutations for this syndrome have been detected in the TREX1, RNASEH2B, RNASEH2C, SAMHD1, ADAR, or IFIH1 genes (Crow YJ et al. 2015).

1. Crow YJ et al (2015) Characterization of human disease phenotypes associated with mutations in TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR, and IFIH1. Am J Med Genet A 167A:296-312.