Biallelic GTF2IRD1 variants in brothers with profound neurodevelopmental disorder: A possible novel disorder involving a critical gene for Williams syndrome

GTF2IRD1, a gene on chromosome 7 which encodes a transcription factor, is of significant clinical interest due to its heterozygous loss as part of the classical deletion associated with Williams-Beuren syndrome (WBS). However, biallelic variants in GTF2IRD1 alone as part of an autosomal recessive disease have not been previously reported. Here, we present two full brothers with variants in trans of GTF2IRD1 at c.1231C > T (p.Arg411Trp) and c.2632C > G (p.Leu878Val). A detailed clinical phenotype is described, which includes severe neurodevelopmental disability, facial dysmorphology, and pectus excavatum. Importantly, out of eight full siblings, only these two brothers harboring both variants in trans present with the profound described phenotype. We present the possibility that these brothers represent the identification of a new syndrome characterized by biallelic variants in GTF2IRD1, which may also have important implications for the molecular etiology of WBS.

GTF2IRD1 overexpression promotes tumor progression and correlates with less CD8+ T cells infiltration in pancreatic cancer

Background: General Transcription Factor II-I Repeat Domain-Containing Protein 1 (GTF2IRD1) is a member of the GTF21 gene family, which encodes a set of multifunctional transcription factors. However, the potential function of GTF2IRD1 in pancreatic cancer (PC) still remains unknown. Study on GTF2IRD1 might provide a new insight into the carcinogenesis and therapeutics of PC.

Methods: In the current study, the clinical significance and potential biological of GTF2IRD1 were evaluated by bioinformatics analysis. The oncogenic role of GTF2IRD1 in PC was also determined using in vitro studies. Possible associations between GTF2IRD1 expression and tumor immunity were analyzed using ESTIMATE algorithm and single-sample Gene Set Enrichment Analysis (ssGSEA).

Results: GTF2IRD1 expression was significantly up-regulated in tumor tissues, and positively associated with higher histologic grade, higher American Joint Committee on Cancer (AJCC) stage, and worse prognosis. Function enrichment analysis demonstrated that GTF2IRD1 may be involved in pancreatic adenocarcinoma pathway, TGF-β signaling pathway, and tumor-infiltrating lymphocyte (TIL) related biological functions, such as T-cell receptor signaling pathway, leukocyte transendothelial migration, resistin as a regulator of inflammation, and regulation of leukocyte-mediated cytotoxicity. Knockdown of GTF2IRD1 expression inhibited cancer cell proliferation, colony formation, and invasion in vitro. ESTIMATE algorithm and ssGSEA demonstrated that GTF2IRD1 expression negatively correlated with the infiltration and anti-tumor activity of TILs, especially for CD8⁺ T cells.

Conclusion: The study demonstrates that GTF2IRD1 overexpression promotes tumor progression and correlates with less CD8⁺ T cells infiltration in PC.

GTF2IRD1 on chromosome 7 is a novel oncogene regulating the tumor-suppressor gene TGFβR2 in colorectal cancer

Chromosome 7q (Ch.7q) is clonally amplified in colorectal cancer (CRC). We aimed to identify oncogenes on Ch.7q that are overexpressed through DNA copy number amplification and determine the biological and clinical significance of these oncogenes in CRC. We identified general transcription factor 2I repeat domain‐containing protein 1 (GTF2IRD1) as a potential oncogene using a CRC dataset from The Cancer Genome Atlas with a bioinformatics approach. We measured the expression of GTF2IRD1 in 98 patients with CRC using immunohistochemistry and RT‐quantitative PCR (RT‐qPCR). The biological effects of GTF2IRD1 expression were explored by gene set enrichment analysis (GSEA). Next, we undertook in vitro cell proliferation and cell cycle assays using siGTF2IRD1‐transfected CRC cells. We further investigated the oncogenic mechanisms through which GTF2IRD1 promoted CRC progression. Finally, we assessed the clinical significance of GTF2IRD1 expression by RT‐qPCR. GTF2IRD1 was overexpressed in tumor cells and liver metastatic lesions. The GSEA revealed a positive correlation between GTF2IRD1 expression and cell cycle progression‐related genes. GTF2IRD1 knockdown inhibited cell proliferation and induced cell cycle arrest in Smad4‐mutated CRC. GTF2IRD1 downregulated the expression of the gene encoding transforming growth factor β receptor 2 (TGFβR2), a tumor‐suppressor gene in Smad4‐mutated CRC. On multivariate analysis, high GTF2IRD1 expression was an independent poor prognostic factor. Clinicopathological analysis showed that GTF2IRD1 expression was positively correlated with liver metastasis. In conclusion, GTF2IRD1 promoted CRC progression by downregulating TGFβR2 and could be a prognostic biomarker on Ch.7q in CRC. GTF2IRD1 could also be a novel oncogene in CRC.

Association of GTF2IRD1-GTF2I polymorphisms with neuromyelitis optica spectrum disorders in Han Chinese patients

Variants at the GTF2I repeat domain containing 1 (GTF2IRD1)–GTF2I locus are associated with primary Sjögren’s syndrome, systemic lupus erythematosus, and rheumatoid arthritis. Numerous studies have indicated that this susceptibility locus is shared by multiple autoimmune diseases. However, until now there were no studies of the correlation between GTF2IRD1–GTF2I polymorphisms and neuromyelitis optica spectrum disorders (NMOSD). This case control study assessed this association by recruiting 305 participants with neuromyelitis optica spectrum disorders and 487 healthy controls at the Department of Neurology, from September 2014 to April 2017. Peripheral blood was collected, DNA extracteds and the genetic association between GTF2IRD1–GTF2I polymorphisms and neuromyelitis optica spectrum disorders in the Chinese Han population was analyzed by genotyping. We found that the T allele of rs117026326 was associated with an increased risk of neuromyelitis optica spectrum disorders (odds ratio (OR) = 1.364, 95% confidence interval (CI) 1.019–1.828; P = 0.037). This association persisted after stratification analysis for aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) positivity (OR = 1.397, 95% CI 1.021–1.912; P = 0.036) and stratification according to coexisting autoimmune diseases (OR = 1.446, 95% CI 1.072–1.952; P = 0.015). Furthermore, the CC genotype of rs73366469 was frequent in AQP4-IgG-seropositive patients (OR = 3.15, 95% CI 1.183–8.393, P = 0.022). In conclusion, the T allele of rs117026326 was associated with susceptibility to neuromyelitis optica spectrum disorders, and the CC genotype of rs73366469 conferred susceptibility to AQP4-IgG-seropositivity in Han Chinese patients. The protocol was approved by the Ethics Committee of West China Hospital of Sichuan University, China (approval number: 2016-31) on March 2, 2016.

Repression of Adipose Tissue Fibrosis through a PRDM16-GTF2IRD1 Complex Improves Systemic Glucose Homeostasis

Adipose tissue fibrosis is a hallmark of malfunction that is linked to insulin resistance and type 2 diabetes; however, what regulates this process remains unclear. Here we show that the PRDM16 transcriptional complex, a dominant activator of brown/beige adipocyte development, potently represses adipose tissue fibrosis in an uncoupling protein 1 (UCP1)-independent manner. By purifying the PRDM16 complex, we identified GTF2IRD1, a member of the TFII-I family of DNA-binding proteins, as a cold-inducible transcription factor that mediates the repressive action of the PRDM16 complex on fibrosis. Adipocyte-selective expression of GTF2IRD1 represses adipose tissue fibrosis and improves systemic glucose homeostasis independent of body-weight loss, while deleting GTF2IRD1 promotes fibrosis in a cell-autonomous manner. GTF2IRD1 represses the transcription of transforming growth factor β-dependent pro-fibrosis genes by recruiting PRDM16 and EHMT1 onto their promoter/enhancer regions. These results suggest a mechanism by which repression of obesity-associated adipose tissue fibrosis through the PRDM16 complex leads to an improvement in systemic glucose homeostasis.

Genetic contributions to visuospatial cognition in Williams syndrome: insights from two contrasting partial deletion patients

Background

Williams syndrome (WS) is a rare neurodevelopmental disorder arising from a hemizygotic deletion of approximately 27 genes on chromosome 7, at locus 7q11.23. WS is characterised by an uneven cognitive profile, with serious deficits in visuospatial tasks in comparison to relatively proficient performance in some other cognitive domains such as language and face processing. Individuals with partial genetic deletions within the WS critical region (WSCR) have provided insights into the contribution of specific genes to this complex phenotype. However, the combinatorial effects of different genes remain elusive.

Methods

We report on visuospatial cognition in two individuals with contrasting partial deletions in the WSCR: one female (HR), aged 11 years 9 months, with haploinsufficiency for 24 of the WS genes (up to GTF2IRD1), and one male (JB), aged 14 years 2 months, with the three most telomeric genes within the WSCR deleted, or partially deleted.

Results

Our in-depth phenotyping of the visuospatial domain from table-top psychometric, and small- and large-scale experimental tasks reveal a profile in HR in line with typically developing controls, albeit with some atypical features. These data are contrasted with patient JB’s atypical profile of strengths and weaknesses across the visuospatial domain, as well as with more substantial visuospatial deficits in individuals with the full WS deletion.

Conclusions

Our findings point to the contribution of specific genes to spatial processing difficulties associated with WS, highlighting the multifaceted nature of spatial cognition and the divergent effects of genetic deletions within the WSCR on different components of visuospatial ability. The importance of general transcription factors at the telomeric end of the WSCR, and their combinatorial effects on the WS visuospatial phenotype are also discussed.

A 1.3-mb 7q11.23 atypical deletion identified in a cohort of patients with williams-beuren syndrome

Williams-Beuren syndrome is a rare multisystem neurodevelopmental disorder caused by a 1.55-1.84-Mb hemizygous deletion on chromosome 7q11.23. The classical phenotype consists of characteristic facial features, supravalvular aortic stenosis, intellectual disability, overfriendliness, and visuospatial impairment. So far, 26-28 genes have been shown to contribute to the multisystem phenotype associated with Williams-Beuren syndrome. Among them, haploinsufficiency of the ELN gene has been shown to cause the cardiovascular anomalies. Identification of patients with atypical deletions has provided valuable information for genotype-phenotype correlation, in which other genes such as LIMK1,CLIP2, GTF2IRD1, or GTF2I have been correlated with specific cognitive profiles or craniofacial features. Here, we report the clinical and molecular characteristics of a patient with an atypical deletion that does not include the GTF2I gene and only partially includes the GTF2IRD1 gene.