Fatal Adult-onset Antibody Deficiency Syndrome in a Patient with Cartilage Hair Hypoplasia

Cartilage hair hypoplasia (CHH) is an autosomal recessive disorder caused by mutations in the ribonuclease mitochondrial RNA-processing (RMRP) gene. Although its most constant feature is metaphyseal dysplasia with short stature, CHH is associated with extraskeletal defects such as thin hair, anemia, immunodeficiency, and increased incidence of lymphomas. The spectrum of immunologic phenotypes in CHH translates into clinical severity. Whereas T-cell deficiency may remain subclinical or may result in severe combined immunodeficiency or Omenn syndrome, humoral immunodeficiency has only rarely been noted in these patients. Here we report the diagnosis of CHH in a woman who presented with severe short stature and a full-blown antibody deficiency, clinically resembling common variable immunodeficiency. Sequencing of the RMRP gene revealed compound heterozygosity for two novel mutations (g.68_69delinsTT and g.76C>T). Despite the late onset of immunodeficiency in the patient, its clinical course was severe, and the patient died 3 years after the first diagnosis.