View clinical trials related to Dwarfism.
Filter by:The purpose of this study is to evaluate i) the effect of multiple doses of vosoritide and ii) the effect of the therapeutic dose of vosoritide compared to human growth hormone (hGH), in children with idiopathic short stature (ISS).
Detect the prevalence of celiac disease in children with unexplained short stature attended at Assiut University Children Hospital.
In the human genome, about 750 genes contain one intron excised by the minor spliceosome. These genes are named U12 genes, and these introns, minor or U12 introns. The minor spliceosome comprises its own set of snRNAs, among which U4atac. Its non-coding gene, RNU4ATAC, has been found mutated in Taybi-Linder (TALS), Roifman (RFMN) and Lowry-Wood syndromes (LWS). These rare developmental disorders associate ante- and post-natal growth retardation, microcephaly, skeletal dysplasia, intellectual disability, retinal dystrophy and immunodeficiency. Their physiopathological mechanisms remain unsolved: the number of U12 genes involved, their identity and function, or the cellular mechanisms impacted by the splicing defect, are still unknown. The hypothesis of the study is that U12 genes coding for primary cilia components are particularly sensitive to minor splicing defects caused by RNU4ATAC mutations. Indeed, a child showing signs of TALS but negative for RNU4ATAC was found to carry a homozygous variant in the RTTN gene, coding for the rotatin protein located at the centrosome and the base of the primary cilia and playing a role in maintaining these structures. In addition, bi-allelic RNU4ATAC mutations were identified in five patients presenting with traits suggestive of the Joubert syndrome (JBTS), a well-characterized ciliopathy. These patients also present with traits typical of TALS/RFMN/LWS. To better understand the causes of these pathologies, a cohort of patients with syndromes associated with bi-allele mutations of the RNU4ATAC or RTTN gene will be gathered, in order to conduct studies on the cells of these patients. Blood samples will be taken, as well as skin biopsies, if possible. These samples will be used to create induced pluripotent stem cell lines. Blood samples will also be collected from the parents of RNU4ATAC patients, to eliminate in transcriptomic analyses expression variations due to differences in genetic background. Biopsies of skin, muscle and brain tissue will be collected on foetuses carrying two-allele RNU4ATAC or RTTN mutations whose parents have had a miscarriage or have chosen to have a medical abortion. The biological samples collected will be used to study the transcription level of U12 genes, the splicing of their pre-messenger RNA, their main cellular functions, and the structural characteristics of tissues and cells.
Our trial aims to evaluate the prevalence of idiopathic short stature among children whose growth is above -2,5SD (AFPA- CRESS/Inserm -CompuGroup Medical 2018 curve) or above -2SD of the parental target size (taking child gender into account), after exclusion of classical pediatric and endocrinologic pathologies, and to evaluate the prevalence of monogenic causes of idiopathic short stature. We propose to perform a two-step study. The first one consists in a standardized multidisciplinary clinico-radiological evaluation of those children to evaluate the real prevalence of idiopathic short stature (ISS) among these patients. The second step consists in performing a whole genome sequencing analysis in the 30 first patients for whom the diagnosis of ISS is confirmed.
This study is a multi-center, retrospective and non-interventional research. In this study, a total of 150 short children who were small for gestational age and had been treated with recombinant human growth hormone (rhGH) are selected for genetic testing. The aims of this study are to analyze the genetic etiology of SGA children with short stature, and to compare the efficacy and safety of rhGH treatment in subjects with different etiologies.
Taybi-Linder syndrome (TALS, OMIM 210710) is a rare autosomal recessive disorder belonging to the group of microcephalic osteodysplastic primordial dwarfisms (MOPD). This syndrome is characterized by short stature, skeletal anomalies, severe microcephaly with brain malformations and facial dysmorphism, and is caused by mutations in RNU4ATAC. Although RNU4ATAC-associated TALS is a recognizable phenotype, an atypical presentation is sometimes observed, thus expanding the clinical spectrum (TALS-like phenotype). This study aims to identify new variants involved in Taybi-Linder syndrome and associated phenotypes (i.e.TALS-like). This non interventional study will be performed on patients with no proven mutation of RNU4ATAC and their blood relatives (19 samples total) by high throughput sequencing and genetic analysis of already collected deoxyribonucleic acid samples. Altogether, such a study will allow a better understanding of the molecular mechanisms responsible for the Taybi-Linder syndrome and Taybi-Linder syndrome-like phenotypes as well as the pathophysiology of these devastating forms of microcephalic dwarfism.