2. Academic Validation
  3. Intragenic CAMTA1 rearrangements cause non-progressive congenital ataxia with or without intellectual disability

Intragenic CAMTA1 rearrangements cause non-progressive congenital ataxia with or without intellectual disability

  • J Med Genet. 2012 Jun;49(6):400-8. doi: 10.1136/jmedgenet-2012-100856.
Julien Thevenon 1,  Estelle Lopez,  Boris Keren,  Delphine Heron,  Cyril Mignot,  Cecilia Altuzarra,  Mylène Béri-Dexheimer,  Céline Bonnet,  Eloi Magnin,  Lydie Burglen,  Delphine Minot,  Jacqueline Vigneron,  Sophie Morle,  Mathieu Anheim,  Perrine Charles,  Alexis Brice,  Louise Gallagher,  Jeanne Amiel,  Emmanuel Haffen,  Corinne Mach,  Christel Depienne,  Diane Doummar,  Marlène Bonnet,  Laurence Duplomb,  Virginie Carmignac,  Patrick Callier,  Nathalie Marle,  Anne-Laure Mosca-Boidron,  Virginie Roze,  Bernard Aral,  Ferechte Razavi,  Philippe Jonveaux,  Laurence Faivre,  Christel Thauvin-Robinet
Affiliations

Affiliation

  • 1 Centre de Génétique et Centre de Référence, Anomalies du Développement et Syndromes Malformatifs, Hôpital d'Enfants, CHU Dijon, Dijon, France.
PMID: 22693284 DOI: 10.1136/jmedgenet-2012-100856
Abstract

Background: Non-progressive congenital ataxias (NPCA) with or without intellectual disability (ID) are clinically and genetically heterogeneous conditions. As a consequence, the identification of the genes responsible for these phenotypes remained limited.

Objective: Identification of a new gene responsible for NPCA and ID. Methods Following the discovery of three familial or sporadic cases with an intragenic calmodulin-binding transcription activator 1 (CAMTA1) rearrangement identified by an array-CGH and recruited from a national collaboration, the authors defined the clinical and molecular characteristics of such rearrangements, and searched for patients with point mutations by direct Sequencing.

Results: Intragenic copy number variations of CAMTA1 were all located in the CG-1 domain of the gene. It segregated with autosomal dominant ID with non-progressive congenital cerebellar ataxia (NPCA) in two unrelated families, and was de novo deletion located in the same domain in a child presenting with NPCA. In the patients with ID, the deletion led to a frameshift, producing a truncated protein, while this was not the case for the patient with isolated childhood ataxia. Brain MRI of the patients revealed a pattern of progressive atrophy of cerebellum medium lobes and superior vermis, parietal lobes and hippocampi. DNA Sequencing of the CG-1 domain in 197 patients with sporadic or familial non-syndromic intellectual deficiency, extended to full DNA Sequencing in 50 patients with ID and 47 additional patients with childhood ataxia, identified no pathogenic mutation.

Conclusion: The authors have evidence that loss-of-function of CAMTA1, a brain-specific calcium responsive transcription factor, is responsible for NPCA with or without ID. Accession numbers CAMTA1 reference sequence used was ENST00000303635. Protein sequence was ENSP00000306522.

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