Meyahealth
HomeGeneticsGeneHARS2 gene
Back to Gene
HARS2 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

HARS2 gene

The HARS2 gene provides instructions for making an enzyme essential for protein synthesis within the mitochondria, the energy-producing centers of cells.

Normal Function

The HARS2 gene provides instructions for making an enzyme called mitochondrial histidyl-tRNA synthetase. This enzyme is important in the production (synthesis) of proteins in cellular structures called mitochondria, the energy-producing centers in cells. While most protein synthesis occurs in the fluid surrounding the nucleus (cytoplasm), some proteins are synthesized in the mitochondria.

During protein synthesis, in either the mitochondria or the cytoplasm, a type of RNA called transfer RNA (tRNA) helps assemble protein building blocks (amino acids) into a chain that forms the protein. Each tRNA carries a specific amino acid to the growing chain. Enzymes called aminoacyl-tRNA synthetases, including mitochondrial histidyl-tRNA synthetase, attach a particular amino acid to a specific tRNA. Mitochondrial histidyl-tRNA synthetase attaches the amino acid histidine to the correct tRNA, which helps ensure that histidine is added at the proper place in the mitochondrial protein.

Health Conditions Related to Genetic Changes

Perrault syndrome

At least two mutations in the HARS2 gene have been found to cause Perrault syndrome. This rare condition is characterized by hearing loss in males and females with the disorder and abnormalities of the ovaries in affected females. The HARS2 gene mutations involved in Perrault syndrome reduce the activity of mitochondrial histidyl-tRNA synthetase. A shortage of functional mitochondrial histidyl-tRNA synthetase prevents the normal assembly of new proteins within mitochondria. Researchers speculate that impaired protein assembly disrupts mitochondrial energy production. However, it is unclear exactly how HARS2 gene mutations lead to hearing problems and ovarian abnormalities in affected individuals.

Other Names for This Gene

  • HARS-related
  • HARSL
  • HARSR
  • hisRS
  • histidine translase
  • histidine tRNA ligase 2, mitochondrial (putative)
  • histidine-tRNA ligase homolog
  • histidyl-tRNA synthetase 2
  • histidyl-tRNA synthetase 2, mitochondrial (putative)
  • HO3
  • PRLTS2
  • probable histidine--tRNA ligase, mitochondrial
  • probable histidine--tRNA ligase, mitochondrial isoform 2
  • probable histidine--tRNA ligase, mitochondrial isoform 3
  • probable histidyl-tRNA synthetase, mitochondrial

Genomic Location

The HARS2 gene is found on chromosome 5.

Frequently Asked Questions

There is no cure that reverses the underlying mitochondrial defect. Management focuses on symptom relief: hearing aids or cochlear implants for hearing loss, hormone replacement or assisted reproductive technologies for ovarian insufficiency, and physical therapy for any balance or coordination issues. Regular monitoring of iron status and metabolic panels is also recommended, as mitochondrial dysfunction can affect multiple systems.
Since HARS2 mutations are inherited in an autosomal recessive pattern, each child of two carriers has a 25% chance of being affected. Genetic counseling can help families understand recurrence risks, discuss preconception testing, and explore options such as prenatal diagnosis or preimplantation genetic testing if desired.
Perrault syndrome typically presents with sensorineural hearing loss in both sexes, often detected in childhood or adolescence. In females, ovarian dysfunction may manifest as primary amenorrhea, reduced ovarian reserve, or infertility. Some patients also report neurological symptoms such as ataxia or tremor, though these are less common. Early recognition of hearing loss and menstrual irregularities can prompt further evaluation.
Diagnosis begins with a detailed clinical history and physical exam, followed by audiologic testing and ovarian imaging. Genetic testing, usually through a targeted gene panel or whole exome sequencing, confirms pathogenic variants in HARS2. Because the condition is rare, referral to a genetics specialist is often advised.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

Meyahealth

Ⓒ 2026. All rights reserved by MEYA

About UsTerms & PolicyFAQ