Phenotypic spectrum and genomics of undiagnosed arthrogryposis multiplex congenita
Annie Laquerrière, Dana Jaber, Emanuela Abiusi, Jérôme Maluenda, Dan Mejlachowicz, Alexandre Vivanti, Klaus Dieterich, Radka Stoeva, Loïc Quevarec, Flora Nolent, Valérie Biancalana, Philippe Latour, Damien Sternberg, Yline Capri, Alain Verloès, Bettina Bessières, Laurence Lœuillet, Tania Attié‐Bitach, Jéléna Martinovic, Sophie Blesson, Florence Petit, Claire Bénéteau, Sandra Whalen, Florent Marguet, Jérôme Bouligand, Delphine Héron, Géraldine Viot, Jeanne Amiel, Daniel Amram, Céline Bellesme, Martine Bucourt, Laurence Faivre, Pierre‐Simon Jouk, Suonavy Khung, Sabine Sigaudy, Anne‐Lise Delezoide, Alice Goldenberg, Marie‐Line Jacquemont, Laëtitia Lambert, Valérie Layet, Stanislas Lyonnet, Arnold Münnich, Lionel Van Maldergem, Juliette Piard, Fabien Guimiot, P. Landrieu, Pascaline Létard, Fanny Pelluard, Laurence Perrin, Marie‐Hélène Saint‐Frison, Haluk Topaloğlu, Laetitia Trestard, Catherine Vincent‐Delorme, Helge Amthor, Christine Barnérias, Alexandra Benachi, Éric Bieth, Élise Boucher, Valérie Cormier‐Daire, Andrée Delahaye‐Duriez, Isabelle Desguerre, B. Eymard, Christine Francannet, Sarah Grotto, Didier Lacombe, Fanny Laffargue, Marine Legendre, Dominique Martin‐Coignard, André Mégarbané, Sandra Mercier, Mathilde Nizon, Luc Rigonnot, Fabienne Prieur, Chloé Quēlin, Hanitra Ranjatoelina-Randrianaivo, Nicoletta Resta, Annick Toutain, Hélène Verhelst, Marie Vincent, Estelle Colin, Catherine Fallet‐Bianco, Michèle Granier, R Grigorescu, Julien Saada, Marie Gonzalès, Anne Guiochon‐Mantel, Jean‐Louis Bessereau, Marcel Tawk, Marta Gut, Cyril Gitiaux, Judith Melki
Abstract
BACKGROUND: Arthrogryposis multiplex congenita (AMC) is characterised by congenital joint contractures in two or more body areas. AMC exhibits wide phenotypic and genetic heterogeneity. Our goals were to improve the genetic diagnosis rates of AMC, to evaluate the added value of whole exome sequencing (WES) compared with targeted exome sequencing (TES) and to identify new genes in 315 unrelated undiagnosed AMC families. METHODS: Several genomic approaches were used including genetic mapping of disease loci in multiplex or consanguineous families, TES then WES. Sanger sequencing was performed to identify or validate variants. RESULTS: expanding the phenotypes associated with these genes. The most frequent cause of AMC was a primary involvement of skeletal muscle (40%) followed by brain (22%). The most frequent mode of inheritance is autosomal recessive (66.3% of patients). In sporadic patients born to non-consanguineous parents (n=60), de novo dominant autosomal or X linked variants were observed in 30 of them (50%). CONCLUSION: New genes recently identified in AMC represent 21% of causing genes in our cohort. A high proportion of de novo variants were observed indicating that this mechanism plays a prominent part in this developmental disease. Our data showed the added value of WES when compared with TES due to the larger clinical spectrum of some disease genes than initially described and the identification of novel genes.