View clinical trials related to Intellectual Deficiency.
Filter by:Intellectual deficiency (ID) is a veritable public health issue because it affects 1 to 3% of the population at large. Currently, in France, the diagnosis is based on clinical expertise, the use of DNA microarray analysis, screening for fragile-X syndrome and, if necessary, a study of target genes depending on the clinical data. Although clinical expertise is not enough to target one gene in particular, these different tools currently lead to diagnosis in only 20% of patients on average (higher percentage in cases of syndromic intellectual deficiency), sometimes after numerous expensive biological examinations. Thanks to high-throughput sequencing (HTS), medical genetics is experiencing a major technological upheaval, originating from the development of sequencing panels of target genes, such as, for example, the DI459 panel, composed of 459 genes implicated in or likely to be implicated in ID, developed by the team in Strasbourg and whole-exome sequencing (WES). The deployment of HTS in diagnosis has occurred at different speeds depending on the country, some of which have been using it in routine diagnosis for several years. The type of strategy to adopt in development anomalies is still a matter of debate in France, in the absence of results from cost-effectiveness analyses; this absence has hampered the implementation of these technologies. In the diagnosis of ID, the DI459 panel has a diagnostic yield of 25%. Data in the literature also show a high efficacy of WES in patients with ID: approximately 32% of genetic diagnoses (progressively increasing thanks to possible reanalysis as knowledge of genomics advances) and 10% of additional diagnoses through the identification of chromosomal micro-rearrangements, making an expected total of 42% of diagnoses. WES could thus replace array-CGH. The cost is higher than that for the DI44 and DI459 panels, but it means that examinations don't have to be repeated sequentially over time if the investigations are negative. The question of medico-economic value is thus central so as to determine which strategy is the most effective. A few medico-economic studies, comparing classical investigations with WES, have already been carried out concerning the use of HTS for diagnostic purposes, but none have concerned ID, or compared panel sequencing with WES. In this context, a medico-economic study is essential in France, because ultimately the choice of the most appropriate HTS strategy in the diagnosis of ID will have major repercussions not only clinical and economic, but also for society at large, on the one hand because of the benefits 1) for the management and prognosis of patients, and 2) for families as they will have improved access to genetic counselling. It is important to note that the Genetic community has never experienced such a huge technological innovation, which will lead to a massive increase in diagnostic yield, thus justifying the interest that the community must give to this innovation.
According to the World Health Organization (WHO), mental retardation (MR) is defined by an intelligence quotient (IQ) < 70 and touches between 1 to 3 % of the general population. Profound mental retardation (QI <25), severe (IQ: 25-40) and moderate (QI : 40-50) have a prevalence of 0,3-0,5% while the prevalence of mild MR, defined by an IQ between 50 and 70 is evaluated to about 1,5 %. The origin of MR can be infectious, toxic, traumatic, genetic or environmental. genetic causes of MR gather the number and structure anomalies of the chromosomes, the genomic microreorganization, monogenic diseases and more rarely other non Mendelian-inherited anomalies like print or epigenetic anomalies, mutations of the mitochondrial genome etc... Genetic causes represents 50% of moderate to severe, whereas environmental factors (malnutrition, cultural deprivation,...) plays an important role in mild MR. The main goal of this study is to get an innovative tool (neuronal distinction of iPSC) that wil allow to study the functionnal impact of mutations uppon genes probably involved in MR like MYT1L. The main criteria associated to characterisation of the tool by the trial is the study of the pluripotency of iPSC obtained and to highlight the mutation of the gene MYT1L in the iPSC. Neurons from the iPSC of the patient and his father du patient wille also be morphologically characterised, but also thanks to the expression of specifically neurals genes. Characteristics of iPSC and neurons from d'iPSC with MYT1L mutation will be compared among the patient and his father, in relation with the same cells coming from the two witnesses.
Corpus callosum agenesis or dysgenesis (CCA) is a major brain malformation (˜1/4000 births) presently diagnosed by prenatal ultrasonography. In about half of the cases, CCA is associated with other anomalies (complex CCA), which usually leads to medical abortion. Syndromes including a CCA are many (hundreds), most of which are also associated with intellectual deficiency (ID). Several genes are involved in such complex CCA. On the other hand, several studies pointed to the favorable cognitive outcome of individuals/fetuses with an apparently isolated CCA (ICCA) during pregnancy in about 70% of cases. However, there are still 30% of cases with ID or developmental delay. The precise incidence and severity of these disorders are presently unclear. Therefore, prenatal counseling of couples facing a prenatal diagnosis of ICCA is still elusive. Our aims are to unravel the genetic causes of CCA by combining phenotypic and genetic analyses in a prospective cohort of patients with CCA and intellectual disability, in order to improve prenatal information.