Cartilage-hair hypoplasia (CHH) is an autosomal recessive chondrodysplasia caused by <i>RMRP</i> (RNA component of mitochondrial RNA processing endoribonuclease) gene mutations.
Cartilage hair hypoplasia (CHH), anauxetic dysplasia 1, and anauxetic dysplasia 2 are rare metaphyseal dysplasias caused by biallelic pathogenic variants in RMRP and POP1, which encode the components of RNAse-MRP endoribonuclease complex (RMRP) in ribosomal biogenesis pathway.
We describe a rare association of testotoxicosis with a metaphyseal chondrodysplasia called cartilage-hair hypoplasia (CHH) and report two brothers with testotoxicosis after 4 years of treatment.
<b>Background:</b> Mutations in <i>RMRP</i>, encoding a non-coding RNA molecule, underlie cartilage-hair hypoplasia (CHH), a syndromic immunodeficiency with multiple pathogenetic mechanisms and variable phenotype.
Mutations in the long noncoding RNA RNase component of the mitochondrial RNA processing endoribonuclease (RMRP) give rise to the autosomal recessive condition cartilage-hair hypoplasia (CHH).
<i>Viperin</i> mRNA is a substrate for endoribonucleolytic cleavage by RNase mitochondrial RNA processing (MRP) and mutations in the RNase MRP small nucleolar RNA (snoRNA) subunit of the RNase MRP complex cause cartilage-hair hypoplasia (CHH), a human developmental condition characterized by metaphyseal chondrodysplasia and severe dwarfism.
Cartilage hair hypoplasia (CHH) or McKusick type metaphyseal chondrodysplasia (MCD) (OMIM # 250250) is due to either the homozygous or compound heterozygous mutations in the nuclear encoded, non-coding RNA gene RMRP.
Patients with cartilage-hair hypoplasia (CHH), a rare metaphyseal chondrodysplasia, manifest severe growth failure, variable immunodeficiency and increased risk of malignancies.
We examined 12 Japanese patients with metaphyseal chondrodysplasia (MCD) for mutations in the ribonuclease mitochondrial RNA processing gene (RMRP), and identified four novel mutations in two patients with typical and atypical cartilage-hair hypoplasia (CHH), a form of MCD characterized by extra-skeletal manifestations including hypoplastic hair and defective immunity.
The major mutation causing CHH in Finns is a 70A --> G nucleotide substitution in the RMRP gene, which encodes the untranslated RNA that is a component of mitochondrial RNA-processing endoribonuclease.