Functional Characterization of A Deformed Epidermal Autoregulatory Factor 1 Gene in Litopenaeus vannamei

Innate immunity is crucial for invertebrate defense against pathogenic infections. Numerous studies have indicated that the Toll-NF-κB pathway plays an important role in this process, particularly in anti-bacterial and anti-fungal immunity. Although the function of this pathway has been studied extensively, there are still uncertainties regarding its role in shrimp. In this study, we investigated the functions of Deformed Epidermal Autoregulatory Factor 1 (LvDEAF1) in Litopenaeus vannamei, a member of the Toll-NF-κB pathway. Our findings revealed that LvDEAF1 interacts with L. vannamei Pellino1 (LvPellino1). LvDEAF1 enhances the promoter activity of certain antimicrobial peptide genes, such as Metchnikowin and Drosomycin, in Drosophila Schneider 2 (S2) cells by binding to the NF-κB binding site. LvDEAF1 and LvPellino1 exhibit positive and synergistic effects. Additionally, the expression of LvDEAF1 is induced by Vibrio parahaemolyticus infection and lipopolysaccharides or zymosan treatment. Knockdown LvDEAF1 expression resulted in a decrease in Penaeidins 4 expression and an increase in the cumulative mortality of shrimp infected with V. parahaemolyticus. These findings indicate that LvDEAF1 plays an important role in the Toll-NF-κB pathway of L. vannamei and is essential for its immune response against pathogens.

A Unique Observation of a Patient with Vulto-van Silfhout-de Vries Syndrome

Introduction: Vulto-van Silfhout-de Vries Syndrome (VSVS; OMIM#615828) is a rare hereditary disease associated with impaired intellectual development and speech, delayed psychomotor development, and behavioral anomalies, including autistic behavioral traits and poor eye contact. To date, 27 patients with VSVS have been reported in the literature. Materials and Methods: We describe a 23-year-old male patient with autism spectrum disorder (ASD) who was admitted to the gastroenterological hospital with signs of pseudomembranous colitis. ASD was first noted in the patient at the age of 2.5 years. Later, he developed epileptic seizures and important growth retardation. Prior to the hospitalization, chromosomal aberrations, Fragile X syndrome, and aminoacidopathies/aminoacidurias associated with ASD were excluded. Whole-genome sequencing (WGS) was prescribed to the patient at 23 years old. Results: The patient had a heterozygous carrier of “de novo” variant c.662C > T (p.S221L) in exon 4 of the DEAF1 gene. c.662C > T had not been previously described in genomic databases. According to the ACMG criteria, this missense variant was considered to be pathogenic. VSVS was diagnosed in the patient. Conclusions: The phenotype of the patient is very similar to the data presented in the world literature. However, growth retardation and cachexia, which have not been described previously in the articles, are of interest.

De novo variants of DEAF1 cause intellectual disability in six Chinese patients

BACKGROUND

It has been reported that de novo heterozygous variants of DEAF1 can cause DEAF1-associated neurodevelopmental disorder. The purpose of this article is to explore the clinical and genetic characteristics of Chinese patients harboring de novo DEAF1 variants.

METHODS

We assembled a cohort of six unrelated patients with de novo variants in DEAF1. Clinical and genetic features of these patients were summarized.

RESULTS

Each child showed intellectual disability (ID)/ global developmental delay (GDD). Severe language impairment was prominent. Behavior problems, seizures, sleep disturbance, and a high pain threshold were common features. DEAF1-related seizures were reported to be difficult to treat or intractable. Seizures in our cohort were almost all treatable. Valproic acid was the most commonly used drug. Five heterozygous missense mutations of DEAF1 gene were identified, three of which (p.W234C, p.L203P, p.H275Q) were not published in literature before.

CONCLUSION

Mutations of DEAF1 gene should be considered in ID/GDD patients with a nonspecific phenotype, comprising intellectual disability, prominent speech delay, abnormal behaviors, especially autism. In our study, DEAF1-related epilepsy is completely treatable in Eastern-Asian individuals when compared to patients in other regions, and valproic acid can be used as a first choice. The knowledge of DEAF1-related neurodevelopmental disorder and the de novo variant database of DEAF1 were expanded.

De novo and biallelic DEAF1 variants cause a phenotypic spectrum

PURPOSE

To investigate the effect of different DEAF1 variants on the phenotype of patients with autosomal dominant and recessive inheritance patterns and on DEAF1 activity in vitro.

METHODS

We assembled a cohort of 23 patients with de novo and biallelic DEAF1 variants, described the genotype-phenotype correlation, and investigated the differential effect of de novo and recessive variants on transcription assays using DEAF1 and Eif4g3 promoter luciferase constructs.

RESULTS

The proportion of the most prevalent phenotypic features, including intellectual disability, speech delay, motor delay, autism, sleep disturbances, and a high pain threshold, were not significantly different in patients with biallelic and pathogenic de novo DEAF1 variants. However, microcephaly was exclusively observed in patients with recessive variants (p < 0.0001).

CONCLUSION

We propose that different variants in the DEAF1 gene result in a phenotypic spectrum centered around neurodevelopmental delay. While a pathogenic de novo dominant variant would also incapacitate the product of the wild-type allele and result in a dominant-negative effect, a combination of two recessive variants would result in a partial loss of function. Because the clinical picture can be nonspecific, detailed phenotype information, segregation, and functional analysis are fundamental to determine the pathogenicity of novel variants and to improve the care of these patients.

Coupling clinical exome sequencing with functional characterization studies to diagnose a patient with familial Mediterranean fever and MED13L haploinsufficiency syndromes

Clinicians should consider that clinical exome sequencing provides the unique potential to disentangle complex phenotypes into multiple genetic etiologies. Further, functional studies on variants of uncertain significance are necessary to arrive at an accurate diagnosis for the patient.

Novel homozygous DEAF1 variant suspected in causing white matter disease, intellectual disability, and microcephaly

DEAF1 encodes a transcriptional binding factor and is a regulator of serotonin receptor 1A. Its protein has a significant expression in the neurons of different brain regions and is involved in early embryonic development. In addition, its role in neural tube development is evident from the knockout mouse as many homozygotes have exencephaly. Heterozygous mutations of this gene have been linked to intellectual disability in addition to the gene's involvement in major depression, suicidal tendencies, and panic disorder. In this clinical report, we describe two children from a consanguineous family with intellectual disability, microcephaly, and hypotonia. The brain MRI of both patients showed bilateral and symmetrical white matter abnormalities, and one of the patients had a seizure disorder. Using whole exome sequencing combined with homozygosity mapping, a homozygous p.R226W (c.676C>T) mutation in DEAF1 was found in both patients. Furthermore, sequencing analysis confirmed complete segregation in tested family members and absence of the mutation in control cohort (n = 650). The mutation is located in a highly conserved structural domain that mediates DNA binding and therefore regulates transcriptional activity of its target molecules. This study indicates, for the first time to our knowledge, a hereditary role of DEAF1 in white matter abnormalities, microcephaly and syndromic intellectual disability.

DEAF1 is a Pellino1-interacting protein required for interferon production by Sendai virus and double-stranded RNA

Double-stranded (ds) RNA of viral origin, a ligand for Melanoma Differentiation-associated gene 5 (MDA5) and Toll-Like Receptor 3 (TLR3), induces the TANK-Binding Kinase 1 (TBK1)-dependent phosphorylation and activation of Interferon Regulatory Factor 3 (IRF3) and the E3 ubiquitin ligase Pellino1, which are required for interferon β (IFNβ) gene transcription. Here, we report that Pellino1 interacts with the transcription factor Deformed Epidermal Autoregulatory Factor 1 (DEAF1). The interaction is independent of the E3 ligase activity of Pellino1, but weakened by the phosphorylation of Pellino1. We show that DEAF1 binds to the IFNβ promoter and to IRF3 and IRF7, that it is required for the transcription of the IFNβ gene and IFNβ secretion in MEFs infected with Sendai virus or transfected with poly(I:C). DEAF1 is also needed for TLR3-dependent IFNβ production. Taken together, our results identify DEAF1 as a novel component of the signal transduction network by which dsRNA of viral origin stimulates IFNβ production.