Furthermore, mutations in RMRP also impair chondrocyte hypertrophy and differentiation, thereby underscoring its critical role in skeletal development.[13] So far, 133 mutations have been described in patients with CHH, of which 90 have been identified in RMRP transcripts and the others in RMRP promoters, with most mutations occurring in highly conserved regions.[14]. Here, RMRP is linked to cartilage-hair hypoplasia.