RMRP

RMRP is a gene that encodes the RNA component of the mitochondrial RNA processing endoribonuclease (RNase MRP), a conserved ribonucleoprotein complex present in eukaryotic cells. The RMRP product is a non-coding RNA that contributes to the catalytic activity and substrate recognition of RNase MRP. The complex participates in multiple RNA-processing pathways, including cleavage events required for precursor ribosomal RNA maturation and the processing of RNA primers involved in mitochondrial DNA replication. Through these activities, RNase MRP influences ribosome biogenesis, mitochondrial function, and cell-cycle regulation.

Pathogenic variants in RMRP cause a spectrum of autosomal recessive skeletal and growth disorders, most notably cartilage-hair hypoplasia (CHH). Clinical features of CHH include short stature, fine sparse hair, variable immunodeficiency, anemia, and an increased risk of certain malignancies. Other phenotypes associated with RMRP mutations include severe metaphyseal dysplasia and anauxetic dysplasia, reflecting variable effects on skeletal development and cellular proliferation.

Diagnosis relies on clinical assessment supported by molecular genetic testing to identify biallelic RMRP mutations. Management is multidisciplinary and symptom-directed, addressing growth, hematologic and immune complications; hematopoietic stem cell transplantation may be considered for severe immunodeficiency. RMRP RNA is evolutionarily conserved and remains an active subject of research for its roles in RNA biology, mitochondrial maintenance, and the molecular basis of related heritable disorders.