Articles scientifiques

Amelogenesis Imperfecta: 1 Family, 2 Phenotypes, and 2 Mutated Genes

2016/ English – Journal of Dental Research – Research Reports: Clinical


M.K. Prasad, S. Laouina, M. El Alloussi, H. Dollfus and A. Bloch-Zupan


« Amelogenesis imperfecta (AI) is a clinically and genetically heterogeneous group of diseases characterized by enamel defects. The authors have identified a large consanguineous Moroccan family segregating different clinical subtypes of hypoplastic and hypomineralized AI in different individuals within the family. Using targeted next-generation sequencing, the authors identified a novel heterozygous nonsense mutation in COL17A1 (c.1873C>T, p.R625*) segregating with hypoplastic AI and a novel homozygous 8-bp deletion in C4orf26 (c.39_46del, p.Cys14Glyfs*18) segregating with hypomineralized-hypoplastic AI in this family. This study highlights the phenotypic and genotypic heterogeneity of AI that can exist even within a single consanguineous family. Furthermore, the identification of novel mutations in COL17A1 and C4orf26 and their correlation with distinct AI phenotypes can contribute to a better understanding of the pathophysiology of AI and the contribution of these genes to amelogenesis. »

Hypophosphatasia: diagnosis and clinical signs – a dental surgeon perspective

2016 / English – International Journal of Paediatric Dentistry 2016; 26: 426–438


Agnès Bloch-Zupan


« Summary
Background. Hypophosphatasia (HPP) is a rareinherited metabolic disease in which mutations in the ALPL gene (encoding tissue-nonspecific alkaline phosphatase) result in varying degrees of enzyme deficiency. HPP manifests in a spectrum of symptoms, including early primary tooth loss (root intact) and alveolar bone mineralisation defects.
Objective. To provide an overview of HPP for dental professionals to help recognise and differentially diagnose patients for appropriate referral to a specialist team.
Methods. A non-systematic review of publications on HPP was performed. »

Detection of a Novel DSPP Mutation by NGS in a Population Isolate in Madagascar

March 2016/English – Journal Frontiers in Physiology – Craniofacial Biology and Dental Research


Agnès Bloch-Zupan*, Mathilde Huckert, Corinne Stoetzel, Julia Meyer, Véronique Geoffroy, Rabisoa W. Razafindrakoto, Saholy N. Ralison, Jean-Claude Randrianaivo, Georgette Ralison, Rija O. Andriamasinoro, Rija H. Ramanampamaharana, Solofomanantsoa E. Randrianazary, Louise H. Ralimanana, Béatrice Richard, Philippe Gorry, Marie-Cécile Manière, Jeanne A. Rasoamananjara, Simone Rakoto Alson and Hélène Dollfus


« A large family from a small village in Madagascar, Antanetilava, is known to present with colored teeth. Through previous collaboration and 4 successive visits in 1994, 2004, 2005, and 2012, we provided dental care to the inhabitants and diagnosed dentinogenesis imperfecta. Recently, using whole exome sequencing we confirmed the clinical diagnosis by identifying a novel single nucleotide deletion in exon 5 of DSPP. This paper underlines the necessity of long run research, the importance of international and interpersonal collaborations as well as the major contribution of next generation sequencing tools in the genetic diagnosis of rare oro-dental anomalies. This study is registered in ClinicalTrials ( under the number NCT02397824. »

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