Cartilage-hair-hypoplasia is a rare autosomal recessive metaphyseal dysplasia due to RMRP (the RNA component of the RNase MRP ribonuclease mitochondrial RNA processing complex) gene mutations.
Cartilage-hair hypoplasia (CHH) is characterized by metaphyseal dysplasia, bone marrow failure, increased risk of malignancies, and a variable degree of immunodeficiency.