Browsing by Author "Munnich, Arnold"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Further Delineation of CANT1 Phenotypic Spectrum and Demonstration of Its Role in Proteoglycan Synthesis
    (WILEY-BLACKWELL, 2012-01-01) Nizon, Mathilde; Huber, Celine; De Leonardis, Fabio; Merrina, Rodolphe; Forlino, Antonella; Fradin, Melanie; Tuysuz, Beyhan; Abu-Libdeh, Bassam Y.; Alanay, Yasemin; Albrecht, Beate; Al-Gazali, Lihadh; Basaran, Sarenur Yilmaz; Clayton-Smith, Jill; Desir, Julie; Gill, Harinder; Greally, Marie T.; Koparir, Erkan; van Maarle, Merel C.; MacKay, Sara; Mortier, Geert; Morton, Jenny; Sillence, David; Vilain, Catheline; Young, Ian; Zerres, Klaus; Le Merrer, Martine; Munnich, Arnold; Le Goff, Carine; Rossi, Antonio; Cormier-Daire, Valerie
    Desbuquois dysplasia (DD) is characterized by antenatal and postnatal short stature, multiple dislocations, and advanced carpal ossification. Two forms have been distinguished on the basis of the presence (type 1) or the absence (type 2) of characteristic hand anomalies. We have identified mutations in calcium activated nucleotidase 1 gene (CANT1) in DD type 1. Recently, CANT1 mutations have been reported in the Kim variant of DD, characterized by short metacarpals and elongated phalanges. DD has overlapping features with spondyloepiphyseal dysplasia with congenital joint dislocations (SDCD) due to Carbohydrate (chondroitin 6) Sulfotransferase 3 (CHST3) mutations. We screened CANT1 and CHST3 in 38 DD cases (6 type 1 patients, 1 Kim variant, and 31 type 2 patients) and found CANT1 mutations in all DD type 1 cases, the Kim variant and in one atypical DD type 2 expanding the clinical spectrum of hand anomalies observed with CANT1 mutations. We also identified in one DD type 2 case CHST3 mutation supporting the phenotype overlap with SDCD. To further define function of CANT1, we studied proteoglycan synthesis in CANT1 mutated patient fibroblasts, and found significant reduced GAG synthesis in presence of beta-D-xyloside, suggesting that CANT1 plays a role in proteoglycan metabolism. Hum Mutat 33:1261-1266, 2012. (c) 2012 Wiley Periodicals, Inc.
  • Thumbnail Image
    Item
    XYLT1 Mutations in Desbuquois Dysplasia Type 2
    (CELL PRESS, 2014-01-01) Bui, Catherine; Huber, Celine; Tuysuz, Beyhan; Alanay, Yasemin; Bole-Feysot, Christine; Leroy, Jules G.; Mortier, Geert; Nitschke, Patrick; Munnich, Arnold; Cormier-Daire, Valerie
    Desbuquois dysplasia (DBQD) is a severe condition characterized by short stature, joint laxity, and advanced carpal ossification. Based on the presence of additional hand anomalies, we have previously distinguished DBQD type 1 and identified CANT1 (calcium activated nucleotidase 1) mutations as responsible for DBQD type 1. We report here the identification of five distinct homozygous xylosyltransferase 1 (XYLT1) mutations in seven DBQD type 2 subjects from six consanguineous families. Among the five mutations, four were expected to result in loss of function and a drastic reduction of XYLT1 cDNA level was demonstrated in two cultured individual fibroblasts. Because xylosyltransferase 1 (XT-I) catalyzes the very first step in proteoglycan (PG) biosynthesis, we further demonstrated in the two individual fibroblasts a significant reduction of cellular PG content. Our findings of XYLT1 mutations in DBQD type 2 further support a common physiological basis involving PG synthesis in the multiple dislocation group of disorders. This observation sheds light on the key role of the XT-I during the ossification process.