The expanding spectrum of COL2A1 gene variants IN 136 patients with a skeletal dysplasia phenotype

• Published in: European journal of human genetics : EJHG Vol. 24; no. 7; pp. 992 - 1000
• Main Authors: Barat-Houari, Mouna, Dumont, Bruno, Fabre, Aurélie, Them, Frédéric Tm, Alembik, Yves, Alessandri, Jean-Luc, Amiel, Jeanne, Audebert, Séverine, Baumann-Morel, Clarisse, Blanchet, Patricia, Bieth, Eric, Brechard, Marie, Busa, Tiffany, Calvas, Patrick, Capri, Yline, Cartault, François, Chassaing, Nicolas, Ciorca, Vidrica, Coubes, Christine, David, Albert, Delezoide, Anne-Lise, Dupin-Deguine, Delphine, El Chehadeh, Salima, Faivre, Laurence, Giuliano, Fabienne, Goldenberg, Alice, Isidor, Bertrand, Jacquemont, Marie-Line, Julia, Sophie, Kaplan, Josseline, Lacombe, Didier, Lebrun, Marine, Marlin, Sandrine, Martin-Coignard, Dominique, Martinovic, Jelena, Masurel, Alice, Melki, Judith, Mozelle-Nivoix, Monique, Nguyen, Karine, Odent, Sylvie, Philip, Nicole, Pinson, Lucile, Plessis, Ghislaine, Quélin, Chloé, Shaeffer, Elise, Sigaudy, Sabine, Thauvin, Christel, Till, Marianne, Touraine, Renaud, Vigneron, Jacqueline, Baujat, Geneviève, Cormier-Daire, Valérie, Le Merrer, Martine, Geneviève, David, Touitou, Isabelle
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01-07-2016
• Subjects: Amino Acid Substitution; Arginine; Arthritis - genetics; Arthritis - pathology; Bone dysplasia; Collagen; Collagen (type II); Collagen Diseases - genetics; Collagen Diseases - pathology; Collagen Type II - chemistry; Collagen Type II - genetics; Congenital diseases; Connective Tissue Diseases - genetics; Connective Tissue Diseases - pathology; Dysplasia; Female; Genes; Genotype & phenotype; Genotypes; Glycine; Hearing Loss, Sensorineural - genetics; Hearing Loss, Sensorineural - pathology; Humans; Life Sciences; Male; Mutation; Myopia; Osteochondrodysplasias - genetics; Osteochondrodysplasias - pathology; Patients; Pedigree; Phenotype; Phenotypes; Protein Domains; Retinal Detachment - genetics; Retinal Detachment - pathology; Skeleton; France
• ISSN: 1018-4813; 1476-5438
• DOI: 10.1038/ejhg.2015.250

Heterozygous COL2A1 variants cause a wide spectrum of skeletal dysplasia termed type II collagenopathies. We assessed the impact of this gene in our French series. A decision tree was applied to select 136 probands (71 Stickler cases, 21 Spondyloepiphyseal dysplasia congenita cases, 11 Kniest dysplasia cases, and 34 other dysplasia cases) before molecular diagnosis by Sanger sequencing. We identified 66 different variants among the 71 positive patients. Among those patients, 18 belonged to multiplex families and 53 were sporadic. Most variants (38/44, 86%) were located in the triple helical domain of the collagen chain and glycine substitutions were mainly observed in severe phenotypes, whereas arginine to cysteine changes were more often encountered in moderate phenotypes. This series of skeletal dysplasia is one of the largest reported so far, adding 44 novel variants (15%) to published data. We have confirmed that about half of our Stickler patients (46%) carried a COL2A1 variant, and that the molecular spectrum was different across the phenotypes. To further address the question of genotype-phenotype correlation, we plan to screen our patients for other candidate genes using a targeted next-generation sequencing approach.