Clinical and Molecular Characterisation of Orofaciodigital Syndromes and Other Clinical Phenotypes Secondary to Mutations in the OFD1 Gene

The aim of this multicentre study will be to better describe the clinical characteristics and the etiological bases of patients with OFD syndrome by identifying new genes involved in OFD syndrome. These results will make it possible, from patients who have been clearly identified from a clinical, cytogenetic and molecular point of view, to determine a study strategy in such patients. The data obtained will be used to guide clinical geneticists in genetic counselling for patients and their families. Identification of the molecular bases of the different OFD syndromes will make it possible to determine whether or not they belong to the group of ciliopathies like type I OFD and to understand their physiopathological bases. This study will also make it possible to better characterise the phenotype of boys with syndromic mental retardation related to the OFD1 gene and thus to define the clinical criteria of the study of this gene in boys with mental retardation. The complete absence of knowledge concerning the genetic bases of OFD syndromes, apart from type I, the presence of a large collection of samples from patients with OFD syndrome at Dijon CHU, the recognition of the diagnostic laboratory for syndromic OFD at the international level as well as the technical platform and expertise in molecular cytogenetic methods including CGH-array and molecular genetics (sequencing, quantitative PCR, fragment analysis) at the Cytogenetics and Molecular Biology laboratories at Dijon CHU justify the implementation of such a study in 2010.