Project description:SHOX mutations and deletions of the downstream regulatory region have been reported in cases with idiopathic short stature (ISS) and Leri-Weill dyschondrosteosis (LWD). Recently, a deletion and duplication of upstream enhancers have been described in ISS. Here, we aimed to evaluate the contribution of upstream copy number variations (CNVs) to the pathogenesis of ISS, to validate the enhancer role of the upstream enhancers in human cells, and to characterize the chromatin architecture of the cis-regulatory landscape of SHOX. CNV analysis of three upstream conserved non-coding elements (CNEs), CNE-5, CNE-3 and CNE-2, in 501 ISS referrals with no established molecular diagnosis revealed two deletions and one duplication. Enhancer activity of the upstream CNEs was corroborated by luciferase assays in human osteosarcoma U2OS cells. In addition, all three CNEs overlap with reported H3K27ac ChIP-seq marks in human embryonic limb buds. To characterize the chromatin interaction profile of the SHOX region, chromosome conformation capture (4C-seq) was performed in chicken embryo limb buds and in U2OS cells, revealing interactions of the upstream CNEs with the SHOX promoter. Moreover, the 4C-seq interaction maps and H3K27ac marks indicated that the cis-regulatory landscape of SHOX encompasses 1 Mb, suggesting additional cis-regulatory elements controlling SHOX.In conclusion, we showed that upstream CNVs of SHOX are rare in ISS and have incomplete penetrance. Chromatin interaction maps, luciferase assays and H3K27ac marks further support an enhancer function for the upstream CNEs. Finally, we demonstrated that the cis-regulatory landscape of SHOX is larger than previously anticipated potentially harboring novel cis-regulatory elements, which may be involved in the pathogenesis of molecularly unsolved ISS cases..
Project description:Deficiency of the human short stature homeobox-containing gene (SHOX) has been identified in several disorders characterized by reduced height and skeletal anomalies such as Turner, Leri-Weill and Langer syndrome as well as idiopathic short stature. Although highly conserved in vertebrates, rodents lack a SHOX orthologue. Here, we compared gene expression profiles of wildtype and SHOX transgenic mouse limbs using microarray experiments to identify SHOX target genes in the developing limb. Limbs of E12.5 mouse embryos were dissected, fore- and hindlimbs were pooled and genotyped for RNA extraction. RNA from 2 to 4 littermates was pooled per genotype (Wildtype and SHOX transgene) and compared. In total, 2 microarray hybridization experiments were performed using RNA from 2 biological replicate samples for each genotype.
Project description:Deficiency of the human short stature homeobox-containing gene (SHOX) has been identified in several disorders characterized by reduced height and skeletal anomalies such as Turner, Leri-Weill and Langer syndrome as well as idiopathic short stature. Although highly conserved in vertebrates, rodents lack a SHOX orthologue. Here, we compared gene expression profiles of wildtype and SHOX transgenic mouse limbs using microarray experiments to identify SHOX target genes in the developing limb.
Project description:Idiopathic short stature is diagnosed by a standing height of less than two standard deviation scores in a specific population adjusted for age and gender and the exclusion of identifiable diseases. A series of studies have confirmed that noncoding RNAs can regulate the chondrocyte proliferation, hypertrophy, and endochondral ossification in the growth plate. In order to analyze and find differentially expressed circRNAs in Idiopathic short stature and healthy controls, we aimed to explore whether differentially expressed circRNAs in idiopathic short stature. Four pairs of blood samples were subjected to microarray analysis using the Arraystar Human CircRNAs Microarray v2 (Arraystar, USA). Compared to normal individuals, in ISS patients, the expression levels of 83 circRNAs were upregulated and those of 62 were downregulated.
Project description:Idiopathic short stature is diagnosed by a standing height of less than two standard deviation scores in a specific population adjusted for age and gender and the exclusion of identifiable diseases. A series of studies have confirmed that noncoding RNAs can regulate the chondrocyte proliferation, hypertrophy, and endochondral ossification in the growth plate. In order to analyze and find differentially expressed ceRNAs (lncRNAs, circRNAs and mRNAs in peripheral blood exosomes of idiopathic short stature and healthy controls, we aimed to explore whether differentially expressed ceRNAs (lncRNAs, circRNAs and mRNAs) in peripheral blood exosomes of idiopathic short stature. Three pairs of peripheral blood exosomes samples were subjected to microarray analysis using the SBC human ceRNA Microarray.
Project description:Short stature homeobox-containing gene, MIM 312865 (SHOX) is located within the pseudoautosomal region 1 (PAR1) of the sex chromosomes. Mutations in SHOX or its downstream transcriptional regulatory elements represent the underlying molecular defect in ~60% of Léri-Weill dyschondrosteosis (LWD) and ~5-15% of idiopathic short stature (ISS) patients. Recently, three novel enhancer elements have been identified upstream of SHOX but to date, no PAR1 deletions upstream of SHOX have been observed that only encompass these enhancers in LWD or ISS patients. We set out to search for genetic alterations of the upstream SHOX regulatory elements in 63 LWD and 100 ISS patients with no known alteration in SHOX or the downstream enhancer regions using a specifically designed MLPA assay, which covers the PAR1 upstream of SHOX. An upstream SHOX deletion was identified in an ISS proband and her affected father. The deletion was confirmed and delimited by array-CGH, to extend ~286 kb. The deletion included two of the upstream SHOX enhancers without affecting SHOX. The 13.3-year-old proband had proportionate short stature with normal GH and IGF-I levels. In conclusion, we have identified the first PAR1 deletion encompassing only the upstream SHOX transcription regulatory elements in a family with ISS. The loss of these elements may result in SHOX haploinsufficiency because of decreased SHOX transcription. Therefore, this upstream region should be included in the routine analysis of PAR1 in patients with LWD, LMD and ISS.
Project description:To elucidate the underlying molecular mechanisms and to better understand the broad phenotypic spectrum of SHOX deficiency, we aimed to identify novel SHOX targets. We analyzed differentially expressed genes in SHOX-overexpressing human fibroblasts (NHDF)
Project description:Purpose:Short stature affects approximately 2%-3% of children, representing one of the most frequent disorders for which clinical attention is sought during childhood. Despite assumed genetic heterogeneity, mutations or deletions in the short stature homeobox-containing gene (SHOX) are frequently detected in subjects with short stature. Idiopathic short stature (ISS) refers to patients with short stature for various unknown reasons. The goal of this study was to screen all the exons of SHOX to identify related mutations. Methods:We screened all the exons of SHOX for mutations analysis in 105 ISS children patients (57 girls and 48 boys) living in Taif governorate, KSA using a direct DNA sequencing method. Height, arm span, and sitting height were recorded, and subischial leg length was calculated. Results:A total of 30 of 105 ISS patients (28%) contained six polymorphic variants in exons 1, 2, 4, and 6. One mutation was found in the DNA domain binding region of exon 4. Three of these polymorphic variants were novel, while the others were reported previously. There were no significant differences in anthropometric measures in ISS patients with and without identifiable polymorphic variants in SHOX. Conclusion:In Saudi Arabia ISS patients, rather than SHOX, it is possible that new genes are involved in longitudinal growth. Additional molecular analysis is required to diagnose and understand the etiology of this disease.
Project description:SHOX gene mutations or haploinsufficiency cause a wide range of phenotypes such as Leri Weill dyschondrosteosis (LWD), Turner syndrome, and disproportionate short stature (DSS). However, this gene has also been found to be mutated in cases of idiopathic short stature (ISS) with a 3-15% frequency. In this study, the multiplex ligation-dependent probe amplification (MLPA) technique was employed to determine the frequency of SHOX gene mutations and their conserved noncoding elements (CNE) in Colombian patients with ISS. Patients were referred from different centers around the county. From a sample of 62 patients, 8.1% deletions and insertions in the intragenic regions and in the CNE were found. This result is similar to others published in other countries. Moreover, an isolated case of CNE 9 duplication and a new intron 6b deletion in another patient, associated with ISS, are described. This is one of the first studies of a Latin American population in which deletions/duplications of the SHOX gene and its CNE are examined in patients with ISS.