Novel Mutation in Boy With Cartilage-hair Hypoplasia

BackgroundCartilage-hair hypoplasia (MIM 250250) is an autosomal recessive disease with diverse clinical manifestations. The clinical phenotypes include variable degrees of bone and hair dysplasia, deficient cellular and/or humoral immunity, and a predisposition to malignancy.MethodsWe performed genetic studies of a patient with disproportionate short stature and brittle scalp hair. Genetic studies were also carried out in the patient's parents.ResultsA novel maternal mutation that consisted of a duplication of 14 nucleotides at position −13 of the RNA component of the RNA component of mitochondrial RNA processing endoribonuclease gene (RMRP; g. −26 to −13 dupTACTACTCTGTGAA, promoter region) and a paternal mutation base substitution of C to T at nucleotide + 230 (designated as + 1 in the transcription initiation site) in the coding sequence of RMRP were detected in this patient.ConclusionA novel maternal RMRP mutation was found in a Chinese boy with typical cartilage-hair hypoplasia.