title: Autoimmune hypoparathyroidism in a 12-year-old girl with McKusick cartilage hair hypoplasia.
abstract: McKusick type metaphyseal chondrodysplasia, or cartilage hair hypoplasia (CHH), is a rare autosomal recessive osteochondrodysplasia secondary to a mutation in the RMRP gene. In addition to the metaphyseal chondrodysplasia and the short-limb dwarfism, patients may present with a multisystemic disease, associating immune deficiency with recurrent infantile or childhood infections, hematological abnormalities, and gastrointestinal dysfunction. The probability of malignancy is increased in these patients, as are disimmune manifestations. We report on a 12-year-old girl with a new mutation of the RMRP gene and a severe multisystemic CHH (hematological and pulmonary lesions, severe immune deficiency, arthritis, pancreatic insufficiency, malabsorption, chronic diarrhea) receiving parenteral nutrition who presented with acute symptomatic hypocalcemia and hypercalciuria associated with the presence of autoantibodies directed against the calcium-sensor receptor. At the same time, there was an important escalation of diarrhea. Corticosteroids led to a progressive improvement of biological signs (hypocalcemia, hypoparathyroidism). By contrast, gastrointestinal symptoms and malabsorption did not improve. To our knowledge, this is the first report of autoimmune hypoparathyroidism in CHH.
authors.affiliation: Service de Néphrologie et Rhumatologie Pédiatriques, Centre de Référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, 59 Bd Pinel, 69677 Bron Cedex, France. justine.bacchetta@chu-lyon.fr
authors.forename: Justine
authors.initials: J
authors.lastname: Bacchetta
authors.forename: Bruno
authors.initials: B
authors.lastname: Ranchin
authors.forename: Anne Sophie
authors.initials: AS
authors.lastname: Brunet
authors.forename: Raymonde
authors.initials: R
authors.lastname: Bouvier
authors.forename: Agnès
authors.initials: A
authors.lastname: Duquesne
authors.forename: Patrick
authors.initials: P
authors.lastname: Edery
authors.forename: Nicole
authors.initials: N
authors.lastname: Fabien
authors.forename: Noël
authors.initials: N
authors.lastname: Peretti
mesh_terms: D015551:Autoimmunity / Q000235:genetics*; D002357:Cartilage Diseases / Q000235:genetics*; D002648:Child; D005260:Female; D005808:Genes, Recessive; D006579:Heterozygote; D006801:Humans; D007011:Hypoparathyroidism / Q000235:genetics*; D009154:Mutation; D010009:Osteochondrodysplasias / Q000235:genetics* / Q000276:immunology