An infant with cartilage-hair hypoplasia due to a novel homozygous mutation in the promoter region of the RMRP gene associated with chondrodysplasia and severe immunodeficiency

• Authors: N. Vatanavicharn , N. Visitsunthorn , T. Pho-iam , O. Jirapongsananuruk , P. Pacharn , K. Chokephaibulkit , C. Limwongse , P. Wasant
• Languages of publication: EN

Abstracts

EN

Cartilage-hair hypoplasia (CHH) is a rare autosomal-recessive disorder characterized by short-limbed dwarfism, sparse hair, and immune deficiency. It is caused by mutations in the RMRP gene, which encodes the RNA component of the mitochondrial RNA-processing ribonuclease (RNase MRP). Several mutations have been identified in its promoter region or transcribed sequence. However, homozygous mutations in the promoter region have been only reported in a patient with primary immunodeficiency without other features of CHH. We report on a Thai girl who first presented with chronic diarrhea, recurrent pneumonia, and severe failure to thrive, without apparently disproportionate dwarfism. The diagnosis of CHH was made after the severe wasting was corrected, and disproportionate growth became noticeable. The patient had the typical features of CHH, including sparse hair and metaphyseal abnormalities. The immunologic profiles were consistent with combined immune deficiency. Mutation analysis identified a novel homozygous mutation, g.-19_-25 dupACTACTC, in the promoter region of the RMRP gene. Identification of the mutation enabled us to provide a prenatal diagnosis in the subsequent pregnancy. This patient is the first CHH case with the characteristic features due to the homozygous mutation in the promoter region of the RMRP gene. The finding of severe immunodeficiency supports that promoter mutations markedly disrupt mRNA cleavage function, which causes cell-cycle impairment.

Keywords

EN

CARTILAGE-HAIR HYPOPLASIA; IMMUNE DEFICIENCY; MUTATION; RMRP GENE

Discipline

• GENETICS: GENETICS

• Publisher: Institute of Plant Genetics, Polish Academy of Sciences
• Journal: Journal of Applied Genetics
• Year: 2010
• Volume: 51
• Issue: 4
• Pages: 523-528

Contributors

author

N. Vatanavicharn

author

N. Visitsunthorn

author

T. Pho-iam

author

O. Jirapongsananuruk

author

P. Pacharn

author

K. Chokephaibulkit

author

C. Limwongse

author

P. Wasant

• Document Type: ARTICLE
• Publication order reference: N. Vatanavicharn, Division of Medical Genetics, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand