Homozygous n.64C>T mutation in mitochondrial RNA-processing endoribonuclease gene causes cartilage hair hypoplasia syndrome in two siblings

Cartilage hair hypoplasia syndrome (OMIM # 250250) is a rare autosomal recessive metaphyseal dysplasia, characterized by disproportionate short stature, hair hypoplasia and variable extra-skeletal manifestations, including immunodeficiency, anemia, intestinal diseases and predisposition to cancers. Cartilage hair hypoplasia syndrome has a broad phenotype and it is caused by homozygous or compound heterozygous mutation in the mitochondrial RNA-processing endoribonuclease on chromosome 9p13. Although it is well known as a primordial dwarfism, descriptions of the prenatal growth are missing. To add further details to the knowledge of the phenotypic spectrum of the disease, we report on two siblings with cartilage hair hypoplasia syndrome, presenting n.64C > T homozygous mutation in the mitochondrial RNA-processing endoribonuclease gene. We describe the prenatal and postnatal growth pattern of the two affected patients, showing severe pre- and postnatal growth deficiency.