Hassan Rokni-Zadeh

Objective: Non‐invasive prenatal testing (NIPT) identifies fetal chromosomal abnormalities by sequencing cell‐free fetal DNA (cffDNA). Recent studies suggest the prediction of viral sequences from NIPT data, but current methods lack cost‐effectiveness for routine use. This study develops a straightforward workflow to investigate potential viral signatures in pregnant women using NIPT data from 888 Iranian participants. Method: Two bioinformatic workflows were compared for predicting viral reads: the traditional method involved mapping reads to the human genome, followed by mapping unmapped reads to viral references, and a direct mapping approach to viral genomes, as proposed in this research. Results: While maintaining reproducibility comparable to the conventional method, the proposed workflow minimizes computational complexity and time usage for data processing. Ultimately, this analysis suggested viral DNA in 24.2% of samples, encompassing 29 distinct species, implying the diversity of the maternal virome. Conclusion: This study presents a computationally efficient workflow for the in silico prediction of viral‐like sequences from routine NIPT data. Further experimental validation is essential to verify the presence, viability, or clinical relevance of these sequences.

Genetic defects that result in the absence of all T cells, including both αβ and γδ T cells, are classified as severe combined immunodeficiency (SCID), a life-threatening condition requiring immediate hematopoietic stem cell transplantation (HSCT) in affected newborns. Previously, patients with a homozygous c.*+1G>A splice variant in the T cell receptor (TCR) α constant chain (TRAC) were found to lack only αβ T cells and demonstrated longer survival compared with SCID patients lacking both αβ and γδ T cells. This observation suggested that γδ T cells might partially compensate for the absence of αβ T cells. Here, we describe two children with biallelic premature stop codons in TRAC. These mutations result in a complete loss of TCRαβ expression on the cell surface and an absence of αβ T cells, leading to severe immunodeficiency and early death. Additionally, we demonstrate that the previously reported c.*+1G>A TRAC variant retains partial activity in vitro, enabling low-level expression of functional TCRαβ. This residual expression likely explains the milder phenotype and extended survival observed in patients carrying this variant. In conclusion, we clarify the nonredundant role of αβ T cells in humans. Our findings show that complete TCRα deficiency causes a SCID-like clinical presentation, whereas partial TCRα deficiency is associated with milder clinical outcomes and longer survival.

We describe humans with rare biallelic loss-of-function PTCRA variants impairing pre–α T cell receptor (pre-TCRα) expression. Low circulating naive αβ T cell counts at birth persisted over time, with normal memory αβ and high γδ T cell counts. Their TCRα repertoire was biased, which suggests that noncanonical thymic differentiation pathways can rescue αβ T cell development. Only a minority of these individuals were sick, with infection, lymphoproliferation, and/or autoimmunity. We also report that 1 in 4000 individuals from the Middle East and South Asia are homozygous for a common hypomorphic PTCRA variant. They had normal circulating naive αβ T cell counts but high γδ T cell counts. Although residual pre-TCRα expression drove the differentiation of more αβ T cells, autoimmune conditions were more frequent in these patients compared with the general population.

STAT6 (signal transducer and activator of transcription 6) is a transcription factor that plays a central role in the pathophysiology of allergic inflammation. We have identified 16 patients from 10 families spanning three continents with a profound phenotype of early-life onset allergic immune dysregulation, widespread treatment-resistant atopic dermatitis, hypereosinophilia with esosinophilic gastrointestinal disease, asthma, elevated serum IgE, IgE-mediated food allergies, and anaphylaxis. The cases were either sporadic (seven kindreds) or followed an autosomal dominant inheritance pattern (three kindreds). All patients carried monoallelic rare variants in STAT6 and functional studies established their gain-of-function (GOF) phenotype with sustained STAT6 phosphorylation, increased STAT6 target gene expression, and TH2 skewing. Precision treatment with the anti–IL-4Rα antibody, dupilumab, was highly effective improving both clinical manifestations and immunological biomarkers. This study identifies heterozygous GOF variants in STAT6 as a novel autosomal dominant allergic disorder. We anticipate that our discovery of multiple kindreds with germline STAT6 GOF variants will facilitate the recognition of more affected individuals and the full definition of this new primary atopic disorder.

The genus Pseudomonas hosts an extensive genetic diversity and is one of the largest genera among Gram-negative bacteria. Type strains of Pseudomonas are well known to represent only a small fraction of this diversity and the number of available Pseudomonas genome sequences is increasing rapidly. Consequently, new Pseudomonas species are regularly reported and the number of species within the genus is constantly evolving. In this study, whole genome sequencing enabled us to define 43 new Pseudomonas species and provide an update of the Pseudomonas evolutionary and taxonomic relationships. Phylogenies based on the rpoD gene and whole genome sequences, including, respectively, 316 and 313 type strains of Pseudomonas, revealed sixteen groups of Pseudomonas and, together with the distribution of cyclic lipopeptide biosynthesis gene clusters, enabled the partitioning of the P. putida group into fifteen subgroups. Pairwise average nucleotide identities were calculated between type strains and a selection of 60 genomes of non-type strains of Pseudomonas. Forty-one strains were incorrectly assigned at the species level and among these, 19 strains were shown to represent an additional 13 new Pseudomonas species that remain to be formally classified. This work pinpoints the importance of correct taxonomic assignment and phylogenetic classification in order to perform integrative studies linking genetic diversity, lifestyle, and metabolic potential of Pseudomonas spp.

The taxonomic affiliation of Pseudomonas isolates is currently assessed by using the 16S rRNA gene, MultiLocus Sequence Analysis (MLSA), or whole genome sequencing. Therefore, microbiologists are facing an arduous choice, either using the universal marker, knowing that these affiliations could be inaccurate, or engaging in more laborious and costly approaches. The rpoD gene, like the 16S rRNA gene, is included in most MLSA procedures and has already been suggested for the rapid identification of certain groups of Pseudomonas. However, a comprehensive overview of the rpoD-based phylogenetic relationships within the Pseudomonas genus is lacking. In this study, we present the rpoD-based phylogeny of 217 type strains of Pseudomonas and defined a cutoff value of 98% nucleotide identity to differentiate strains at the species level. To validate this approach, we sequenced the rpoD of 145 environmental isolates and complemented this analysis with whole genome sequencing. The rpoD sequence allowed us to accurately assign Pseudomonas isolates to 20 known species and represents an excellent first diagnostic tool to identify new Pseudomonas species. Finally, rpoD amplicon sequencing appears as a reliable and low-cost alternative, particularly in the case of large environmental studies with hundreds or thousands of isolates.

The draft genome sequence of wheat rhizosphere isolate Pseudomonas sp. strain SWRI103 is reported. This strain carries several gene clusters encoding nonribosomal peptide synthetases (NRPSs), including a system for cyclic lipopeptide (CLP) production, and genes for carotenoid biosynthesis.

The prevalence of primary immunodeficiency (PID) is rather high in Iran compared to the world average, mainly due to the high rate of consanguineous marriage. Despite that, little genetic information is available about primary immunodeficiencies in Iran. Autosomal recessive hyper IgE syndrome (AR-HIES) is a severe type of immunodeficiency, mainly caused by mutations in the dedicator of cytokinesis 8 (DOCK8). Rapid and precise diagnoses of patients suffering from AR-HIES can help to manage the patients and reach properly the treatment decision. However, in regions with low financial resources and limited expertise, deep phenotyping is uncommon. Therefore, an exome-first approach is helpful to make a genetic-based diagnosis. In the present study, whole-exome sequencing (WES) was applied to detect causative mutations in three unrelated primary immunodeficient patients with poor clinical information. One of the cases was a deceased patient with suspected hyper IgE syndrome (HIES) whose parents were subjected to WES. As a result, three novel pathogenic variants were detected in the DOCK8 gene, including two splicing sites (c.4241+1G>T and c.4886+1G>T) and one-stop-gain (c.4201G>T, p.Glu1401Ter) variants. Sanger sequencing confirmed the mutations’ segregation in corresponding families. Further immunological investigations confirmed that HIES in the studied probands. The presence of frontal bossing and broad nose in one of the studied cases, in addition to the typical clinical presentation of DOCK8-AR-HIES, is notable. This work suggests that an exome-first approach can be a valuable alternative strategy for precise diagnosis of primary immunodeficiency patients.

Severe combined immunodeficiency (SCID) comprises a heterogeneous group of genetic disorders caused by early defects in the development and function of T cells. Other lymphocyte lineages (B and/or natural killer cells) are variably affected. With a worldwide frequency of approximately 1:50,000 live births, SCID may result from diverse mutations in over 16 genes. Whole-exome sequencing (WES) provides an opportunity for parallel screening of all those genes. This approach is also useful for genetic diagnosis in parents whose infant expired before genetic testing. Here, we describe a heterozygous novel non-frameshift deletion (c.587_598del p.196_199del) in the adenosine deaminase (ADA) gene identified by WES in healthy parents of an expired child with SCID. The mutation was subsequently confirmed to be homozygous in the deceased baby whose left-over blood sample volume was insufficient for direct WES analysis. In conclusion, we here describe a novel mutation in ADA, a well-known SCID gene.

The draft genome sequence of Pseudomonas aeruginosa LMG 1272, isolated from mushroom, is reported here. This strain triggers formation of a precipitate (“white line”) when cocultured with Pseudomonas tolaasii . However, LMG 1272 lacks the capacity to produce a cyclic lipopeptide that is typically associated with white line formation, suggesting the involvement of a different diffusible factor.