Mild Phenotype Research Articles

Sotos syndrome in two generations - a reminder that high suspicion is needed in milder phenotypes

Sotos syndrome in two generations - a reminder that high suspicion is needed in milder phenotypes

Brainstem Chipmunk Sign: A Diagnostic Imaging Clue across All Subtypes of Alexander Disease.

While classic brain MR imaging features of Alexander disease have been well-documented, lesional patterns can overlap with other leukodystrophies, especially in the early stages of the disease or in milder phenotypes. We aimed to assess the utility of a new neuroimaging sign to help increase the diagnostic specificity of Alexander disease. A peculiar bilateral symmetric hyperintense signal on T2-weighted images affecting the medulla oblongata was identified in an index patient with type I Alexander disease. Subsequently, 5 observers performed a systematic MR imaging review for this pattern by examining 55 subjects with Alexander disease and 74 subjects with other leukodystrophies. Interobserver agreement was assessed by the κ index. Sensitivity, specificity, and receiver operating characteristic curves were determined. The identified pattern was present in 87% of subjects with Alexander disease and 14% of those without Alexander disease leukodystrophy (P < .001), 3 with vanishing white matter, 4 with adult polyglucosan body disease, and 3 others. It was found equally in both type I and type II Alexander disease (28/32, 88% versus 18/21, 86%; P = .851) and in subjects with unusual disease features (2/2). Sensitivity (87.3%; 95% CI, 76.0%-93.7%), specificity (86.5%; 95% CI, 76.9%-92.5%), and interobserver agreement (κ index = 0.82) were high. The identified pattern in the medulla oblongata, called the chipmunk sign due to its resemblance to the face of this rodent, is extremely common in subjects with Alexander disease and represents a diagnostic tool that can aid in early diagnosis, especially in subjects with otherwise atypical MR imaging findings and/or clinical features.

γ-TuRCs and the augmin complex are required for the development of highly branched dendritic arbors in Drosophila.

Microtubules are nucleated by γ-tubulin ring complexes (γ-TuRCs) and are essential for neuronal development. Nevertheless, γ-TuRC depletion has been reported to perturb only higher-order branching in elaborated Drosophila larval class IV dendritic arborization (da) neurons. This relatively mild phenotype has been attributed to defects in microtubule nucleation from Golgi outposts, yet most Golgi outposts lack associated γ-TuRCs. By analyzing dendritic arbor regrowth in pupae, we show that γ-TuRCs are also required for the growth and branching of primary and secondary dendrites, as well as for higher-order branching. Moreover, we identify the augmin complex (hereafter augmin), which recruits γ-TuRCs to the sides of pre-existing microtubules, as being required predominantly for higher-order branching. Augmin strongly promotes the anterograde growth of microtubules in terminal dendrites and thus terminal dendrite stability. Consistent with a specific role in higher-order branching, we find that augmin is expressed less strongly and is largely dispensable in larval class I da neurons, which exhibit few higher-order dendrites. Thus, γ-TuRCs are essential for various aspects of complex dendritic arbor development, and they appear to function in higher-order branching via the augmin pathway, which promotes the elaboration of dendritic arbors to help define neuronal morphology.

Progression, reliability, predicting parameters and sample size calculations for quantitative fundus autofluorescence measures in ABCA4-related retinopathy

Background/aimsTo investigate the progression of quantitative autofluorescence (qAF) measures and the potential as clinical trial endpoint in ABCA4-related retinopathy.MethodsIn this longitudinal monocentre study, 64 patients with ABCA4-related retinopathy (age (mean±SD),...

A protective role of CD4+ T cells during Staphylococcus aureus craniotomy infection

Abstract Craniotomy is a neurosurgery performed to resolve severe neurological complications. Despite prophylaxis, nearly 1-3% of craniotomies are complicated by infection, with approximately half attributed to Staphylococcus aureus (S. aureus). Using our novel mouse model, we established a protective role for CD4+ T cells during S. aureus craniotomy infection. Rag1 knock out (KO) mice or animals treated with anti-CD4 Ab showed significantly elevated bacterial burden, suggesting an important role for adaptive immunity in controlling infection. These findings were corroborated in mice treated with VLA-4 and LFA-1 Abs, underscoring the importance of peripheral CD4+ T cell responses. scRNA-seq revealed phenotypic heterogeneity within brain CD3+ infiltrates with CD4+ cells being most predominant that were typified by robust inflammatory and glycolytic profiles. CD4+ T cells displayed attributes of both Th1 and Th17 phenotypes, whose functional importance was validated in vivo as adoptive transfer of either Th1 or Th17 cells prevented S. aureus outgrowth in Rag1 KO mice. Interestingly, milder phenotypes were observed in IL-17A/F or IFN-γ KO mice, suggesting a redundant and cooperative role of both Th1 and Th17 driven responses. This was confirmed by treatment of IFN-γ KO mice with IL-17A/F neutralizing Ab, which recapitulated phenotypes of Rag1 KO animals. Collectively, our results implicate a critical role for CD4+ T cells in S. aureus containment during craniotomy infection.

Abstract 1154: Length And Proximal Extent Of Occlusion Dictates Severity Of Disease In A Mini-swine Model Of PAD

Background: There is ongoing need for large animal models of peripheral artery disease (PAD) that replicate human disease. We present mild (MI), moderate (MD) and Severe (S) phenotypes of PAD in an Ossabaw mini-swine platform. Methods: Metabolic syndrome was induced in swine (N=16; age= 4 mo) with a high fat/fructose/sodium diet for 8 weeks. Ischemia induction (T0) consisted of: (1) open ligation and resection of R Superficial Femoral Artery (SFA) for MI(N=4); (2) endovascular coil occlusion of R External Iliac Artery (REIA), RSFA and popliteal artery for MD (N=9); and (3) coil occlusion of REIA, RSFA, and right internal iliac artery (RIIA) for S (N=4). At 4 weeks (T4) and 8 (T8), all swine underwent angiography via carotid access, and bilateral gastrocnemius biopsy. All swine had measurements of ankle brachial indices (ABIs), and calf muscle tissue oximetry (STO 2 ) measurements at T0, T4 and T8, along with weekly measurement of walking performance on a treadmill (WP). Results: At T4 and T8 R ABI were increasingly decreased from MI to MD to S (table 1). Mean STO 2 difference between R and L calf at T4 and T8 had no changes in MI, while the differences were larger in S compared to MD (table 1). WP was increasingly decreased from MI to MD to S (table 1). The artery that grew the most on angiography at T4 and T8 were R profunda artery (RPFA) in MI; RIIA in MD; and LIIA in S (table 1). In MI, R PFA had faster flow at T4 and T8 compared to L PFA. At T4, MD and S had similar delays of RPFA reconstitution, this improved at T8 in MD but did not in S (table 1). On histology, MI had no obvious myopathy, MD and S had moderate and severe myopathy respectively. All S subjects developed poorly-healing ischemic ulcers. Conclusion: Length and proximal extent of occlusion dictated the characteristics and severity of phenotypes in our Ossabaw swine model of PAD. This mirrors PAD in humans and can be used to develop therapies for different disease severities.

Empagliflozin Extends Lifespan While Reducing Physical Activity in Drosophila Melanogaster: Insights into Non-Glycemic Pharmacological Effects

Sodium-glucose cotransporter 2 inhibitors (SGLT2i), such as empagliflozin (EMPA), are primarily used to manage hyperglycemia in type 2 diabetes (T2D). Beyond their role in glycemic control, SGLT2i can elicit off-target effects, including induction of a mild energetic stress phenotype—a state previously associated with increased longevity in various organisms. Drosophila melanogaster lack the SGLT2 protein and, therefore, can be used to model the effects of SGLT2i independent of renal glucose reuptake. We tested the hypothesis that EMPA would promote and increase longevity and physical activity (PA) by providing adult virgin female Drosophila with either DMSO (vehicle) or EMPA in the diet at concentrations of 5 μM, 25 μM, and 50 μM. EMPA treatment resulted in a significant extension of median lifespan at all concentrations: 4% (p=0.049) for 5 μM, 24% (p=0.035) for 25 μM, and 8% (p=0.025) for 50 μM, compared with DMSO. A linear mixed model analysis also demonstrated significant interactions between EMPA treatment and time on PA levels—5 μM (p=0.001), 25 μM (p=0.04), and 50 μM (p=5.85e-07)—indicating a pronounced reduction in PA over time in EMPA-treated groups compared with DMSO. Our findings that EMPA promotes longevity and lowers physical activity in Drosophila demonstrate that SGLT2i can have significant physiologic impacts that are independent of inhibition of SGLT2. Supported by funding from the Valley Fellowship (Oregon State University) awarded to SAN. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Assessment of Mitochondrial Function in a Mouse Model of Mild Chronic Kidney Disease Induced by High-Fat and High-Salt Diet

Intro: Kidneys are known for high energy demands involved in active transport and are thus highly oxidative organs, consuming the second-highest amount of oxygen per gram of tissue at rest (only exceeded by the heart). Chronic kidney disease (CKD) is a complex disorder that presents substantial challenges in understanding its pathophysiological mechanisms, including mitochondrial alterations. However, there are no established mouse models that recapitulate the CKD phenotype observed in humans.Hypothesis: We hypothesized that a high-fat, high-salt diet would induce a mild CKD phenotype and mitochondrial dysfunction in mice. Methods: We subjected C57Bl/6 mice to a high-fat (42%) and high-salt (8% NaCl) diet (HF/HNaCl) or standard chow diet for 16 weeks (n=4 per group). Additionally, we conducted comprehensive investigations into mitochondrial function, focusing on state 3 mitochondrial oxygen consumption (Oroboros O2K) and adenosine triphosphate (ATP) production (Horiba Fluoromax). Differences between groups were determined using Student’s t-tests. Results: HF/HNaCl feeding resulted in polyurea indicated by an increase in 24-hour urine output (Chow: 1.5 ± 0.2 mL; HF/HNaCl: 3.7 ± 0.8 mL; p=0.05) and a 30% reduction in glomerular filtration rate compared to chow-fed animals (Chow: 911.2 ± 107.8 μL/min/100g; Hf/HNaCl: 639.5 ± 25.9 μL/min/100g; p=0.08), indicative of the development of mild kidney disease. Although subtle changes were observed in mitochondrial oxygen consumption and ATP production, the alterations were not statistically significant. Discussion: Our findings suggest that the induced mild CKD state via the dietary regimen led to moderate renal impairment without substantial impacts on mitochondrial respiratory capacity and ATP synthesis. The establishment of this mouse model provides a valuable platform for further investigations into the complex interplay between renal dysfunction and mitochondrial dynamics in the context of mild CKD, offering insights that may pave the way for the development of targeted therapeutic interventions for this prevalent and debilitating condition. This project was supported by grants from the National Institutes of Health. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

SARS-CoV-2-ORF3a variant Q57H reduces its pro-apoptotic activity in host cells

Background Mutations in the viral genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can enhance its pathogenicity by affecting its transmissibility, disease severity, and overall mortality in human populations. In addition to mutations within the coding region of SARS-CoV-2 structural proteins, there have been reports of mutations in other SARS-CoV-2 proteins that affect virulence, such as open reading frame 3a (ORF3a), which is involved in viral replication. The expression of ORF3a in host cells activates cell death signaling, leading to tissue damage, which affects the severity of COVID-19. The ORF3a-Q57H variant is the most frequent and recurrent variant of ORF3a and is likely associated with increased transmissibility but lower mortality in the 4th epidemic wave of COVID-19 in Hong Kong. Computational structural modeling predicted that the Q57H variant destabilizes the protein structure of ORF3a, which may result in reduced protein expression in human cells. However, it is still unknown how this mutation affects ORF3a protein function and, if so, whether it can change the severity of host cell damage. Methods Plasmids carrying SARS-CoV-2-ORF3a from Wuhan-Hu-1 strain (i.e., wild-type; WT) and its variant Q57H were transiently transfected into HEK293T cells and used for biochemical and cell biological assays. Results SARS-CoV-2-ORF3a-Q57H variant exhibits higher protein expression than WT, but ORF3a-Q57H expression results in less apoptosis in host cells compared to WT via lower activation of the extrinsic apoptotic pathway. Conclusion The relatively mild phenotype of the SARS-CoV-2-ORF3a-Q57H variant may result from alterations to ORF3a function by this mutation, rather than its protein expression levels in host cells.

Immunogenicity of COVID-19 booster vaccination in IEI patients and their one year clinical follow-up after start of the COVID-19 vaccination program.

Previous studies have demonstrated that the majority of patients with an inborn error of immunity (IEI) develop a spike (S)-specific IgG antibody and T-cell response after two doses of the mRNA-1273 COVID-19 vaccine, but little is known about the response to a booster vaccination. We studied the immune responses 8 weeks after booster vaccination with mRNA-based COVID-19 vaccines in 171 IEI patients. Moreover, we evaluated the clinical outcomes in these patients one year after the start of the Dutch COVID-19 vaccination campaign. This study was embedded in a large prospective multicenter study investigating the immunogenicity of COVID-19 mRNA-based vaccines in IEI (VACOPID study). Blood samples were taken from 244 participants 8 weeks after booster vaccination. These participants included 171 IEI patients (X-linked agammaglobulinemia (XLA;N=11), combined immunodeficiency (CID;N=4), common variable immunodeficiency (CVID;N=45), isolated or undefined antibody deficiencies (N=108) and phagocyte defects (N=3)) and 73 controls. SARS-CoV-2-specific IgG titers, neutralizing antibodies, and T-cell responses were evaluated. One year after the start of the COVID-19 vaccination program, 334 study participants (239 IEI patients and 95 controls) completed a questionnaire to supplement their clinical data focusing on SARS-CoV-2 infections. After booster vaccination, S-specific IgG titers increased in all COVID-19 naive IEI cohorts and controls, when compared to titers at 6 months after the priming regimen. The fold-increases did not differ between controls and IEI cohorts. SARS-CoV-2-specific T-cell responses also increased equally in all cohorts after booster vaccination compared to 6 months after the priming regimen. Most SARS-CoV-2 infections during the study period occurred in the period when the Omicron variant had become dominant. The clinical course of these infections was mild, although IEI patients experienced more frequent fever and dyspnea compared to controls and their symptoms persisted longer. Our study demonstrates that mRNA-based booster vaccination induces robust recall of memory B-cell and T-cell responses in most IEI patients. One-year clinical follow-up demonstrated that SARS-CoV-2 infections in IEI patients were mild. Given our results, we support booster campaigns with newer variant-specific COVID-19 booster vaccines to IEI patients with milder phenotypes.

Further characterization of ARSK-related mucopolysaccharidosis type 10.

Mucopolysaccharidosis type 10 is caused by biallelic variants in ARSK, which encodes for a lysosomal sulfatase. To date, seven patients with a mild phenotype resembling spondyloepiphyseal dysplasia or multiple epiphyseal dysplasia have been described. In this report, we present two novel ARSK variants and report clinical and radiological findings of three patients. The patients' initial complaints were hip or knee pain and a waddling gait. All patients showed normal intelligence, normal hearing and eye examinations, and none had organomegaly. While typical dysostosis multiplex findings were not observed, mild platyspondyly with anterior beaking of some vertebral bodies, irregular vertebral endplates, wide ribs, inferior tapering of the ilea with a poorly developed acetabulum, irregularity of the central part of the femoral head, delayed ossification of the carpals were noted. Remarkably, all patients showed metaphyseal striation of the long bones, a crucial diagnostic clue to identify ARSK-related MPS type 10. Interestingly, vertebral involvement regressed during follow-up. On the other hand, hip dysplasia progressed in all patients. In conclusion, this study provides valuable long-term results on a recently discovered form of MPS.

The small iron-deficiency-induced protein OLIVIA and its relation to the bHLH transcription factor POPEYE.

Iron (Fe) is a crucial micronutrient needed in many metabolic processes. To balance needs and potential toxicity, plants control the amount of Fe they take up and allocate to leaves and seeds during their development. One important regulator of this process is POPEYE (PYE). PYE is a Fe deficiency-induced key bHLH transcription factor (TF) for allocation of internal Fe in plants. In the absence of PYE, there is altered Fe translocation and plants develop a leaf chlorosis. NICOTIANAMINE SYNTHASE4 (NAS4), FERRIC-REDUCTION OXIDASE3 (FRO3), and ZINC-INDUCED FACILITATOR1 (ZIF1) genes are expressed at higher level in pye-1 indicating that PYE represses these genes. PYE activity is controlled in a yet unknown manner. Here, we show that a small Fe deficiency-induced protein OLIVIA (OLV) can interact with PYE. OLV has a conserved C-terminal motif, that we named TGIYY. Through deletion mapping, we pinpointed that OLV TGIYY and several regions of PYE can be involved in the protein interaction. An OLV overexpressing (OX) mutant line exhibited an enhanced NAS4 gene expression. This was a mild Fe deficiency response phenotype that was related to PYE function. Leaf rosettes of olv mutants remained smaller than those of wild type, indicating that OLV promotes plant growth. Taken together, our study identified a small protein OLV as a candidate that may connect aspects of Fe homeostasis with regulation of leaf growth.

Characteristic phenotypes of ADH5/ALDH2 deficiency during childhood

ADH5/ALDH2 deficiency is a rare inherited syndrome characterized by short stature, microcephaly, delayed mental development, and hematopoietic dysfunction and has recently been proposed as a disease paradigm. Acute and severe presentations include aplastic anemia, myelodysplastic syndrome, or leukemia, requiring bone marrow transplantation during childhood. Conversely, non-hematological manifestations may exhibit a prolonged and nonspecific clinical trajectory, with growth failure and developmental delay, most of which are often overlooked, particularly in patients with milder symptoms. Here, we describe the clinical course of a girl with a wide spectrum of clinical presentations, including nonspecific hematopoietic disorders, growth retardation, mild developmental delay, amblyopia, hemophagocytic lymphohistiocytosis, and verruca vulgaris, culminating in a genetic diagnosis of AMeD syndrome at 12 years of age. We also summarized the clinical manifestations of previously reported cases of AMeD syndrome. Cumulatively, 13 females and 5 males have been documented, with a cardinal triad of symptoms, aplastic anemia, short stature, and intellectual disability. Additional characteristic observations included pigmentary deposition in approximately half of the cases and skeletal difficulties in one-quarter. We propose that early diagnosis of patients who exhibit relatively mild phenotypes of skin or skeletal lesions is important for managing and improving the quality of life of patients with AMeD syndrome.

Nusinersen in adults with type 3 spinal muscular atrophy: long-term outcomes on motor and respiratory function.

Nusinersen was approved for 5q spinal muscular atrophy (SMA), irrespective of age, SMA type or functional status. Nonetheless, long-term data on adults with milder phenotypes are scarce. We aimed to characterize evolution on motor and respiratory function in our cohort of adults with type 3 SMA. We conducted a longitudinal retrospective single-center study, including adults (≥18years) with type 3 SMA under nusinersen for > 22months. We reported on motor scores and spirometry parameters. Ten patients were included, with a median follow-up of 34months (range = 22-46). Four patients (40%) were walkers. None used non-invasive ventilation. In Revised Upper Limb Module (RULM) and Expanded Hammersmith Functional Motor Scale (HFMSE), difference of medians increased at 6, 22 and 46months comparing to baseline (-0.5 vs. + 1.5 vs. + 2.5 in RULM; + 4.0 vs. + 7.5 vs. + 6.0 in HFMSE). Two (50%) walkers presented a clinically meaningful improvement in 6-min walk distance. We did not report any clinically meaningful decrement in motor scores. Spirometry parameters showed an increasing difference of medians in maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) (-3 vs. + 13.4 vs. + 28.7 percentage points of predicted value for MIP; + 11.8 vs. + 13.1 vs. 13.3 percentage points of predicted value for MEP). Our cohort supports a sustained benefit of nusinersen in adults with type 3 SMA, in motor and respiratory function. Multicentric studies are still warranted.

Epidermolysis Bullosa: Two rare case reports of COL7A1 and EBS-GEN SEV KRT14 variants with review of literature

EpidermolysisBullosa is a rare hereditary skin condition that causes blisters. Genes encoding structural proteins at or near the dermal-epidermal junction are mutated recessively or dominantly, and this is the primary cause of EB. Herein, two Chinese boys were diagnosed with the condition, each with a different variant in a gene that serves as a reference for EB genetic counseling. Skincare significantly impacted their prognosis and quality of life.Case presentationTwo Chinese boys, with phenotypically normal parents, have been diagnosed with distinct blister symptoms, one with Dominant Dystrophic Epidermolysis Bullosa and the other with a severe form of Epidermolysis Bullosa Simplex. The first patient had a G-to-A variant in the COL7A1 allele, at nucleotide position 6163 which was named “G2055A”. The proband is heterozygous for Dystrophic Epidermolysis Bullosa due to a COL7A1 allele with a glycine substitution at the triple helix domain. A similar variant has been discovered in his mother, indicating its potential transmission to future generations. Another patient had severe Epidermolysis Bullosa Simplex with a rare c.377T > A variant resulting in substitution of amino acid p.Leu126Arg (NM_000526.5 (c.377T > G, p.Leu126Arg) in the Keratin 14 gene. In prior literature, Keratin 14 has been associated with an excellent prognosis. However, our patient with this infrequent variant tragically died from sepsis at 21 days old. There has been a reported occurrence of the variant only once.ConclusionOur study reveals that Epidermolysis Bullosa patients with COL7A1 c.6163G > A and KRT14 c.377T>A variants have different clinical presentations, with dominant forms of Dystrophic EB having milder phenotypes than recessive ones. Thus, the better prognosis in the c.6163G > A patient. Furthermore, c.377T>A patient was more prone to infection than the patient with c.6163G>A gene variant. Genetic testing is crucial for identifying the specific variant responsible and improving treatment options.

A Novel Human Interleukin-23A Overexpressing Mouse Model of Systemic Lupus Erythematosus.

Interleukin-23 (IL-23) is a crucial cytokine implicated in chronic inflammation and autoimmunity, associated with various diseases such as psoriasis, psoriatic arthritis, and systemic lupus erythematosus (SLE). This study aimed to create and characterize a transgenic mouse model overexpressing human IL-23A (TghIL-23A), providing a valuable tool for investigating the pathogenic role of human IL-23A and evaluating the efficacy of anti-human IL-23A therapeutics. TghIL-23A mice were generated via microinjection of CBA × C57BL/6 zygotes with a fragment of the human IL23A gene, flanked by its 5'-regulatory sequences and the 3' untranslated region of human β-globin. The TghIL-23A pathology was assessed through hematologic and biochemic analyses, cytokine and antinuclear antibody detection, and histopathologic examination of skin and renal tissues. The response to the anti-human IL-23A therapeutic agent guselkumab was evaluated in groups of eight mixed-sex mice receiving subcutaneous treatment twice weekly for 10 weeks using clinical, biomarker, and histopathologic readouts. TghIL-23A mice exhibited interactions between human IL-23A and mouse IL-23/IL-12p40 and developed a chronic multiorgan autoimmune disease marked by proteinuria, anti-double-stranded DNA antibodies, severe inflammatory lesions in the skin, and milder phenotypes in the kidneys and lungs. The TghIL-23A pathologic features exhibited significant similarities to those observed in human patients with SLE, and they were reversed following guselkumab treatment. We have generated and characterized a novel genetic mouse model of SLE, providing proof-of-concept for the etiopathogenic role of human IL-23A. This new model has a normal life span and integrates several characteristics of the human disease's complexity and chronicity, making it an attractive preclinical tool for studying IL-23-dependent pathogenic mechanisms and assessing the efficacy of anti-human IL-23A or modeled disease-related therapeutics.

Interferon-Alpha Induces Psoriatic Inflammation in Mice by Phosphorylating FOXO3.

Psoriasis is a chronic, immune-mediated inflammatory skin disease characterized by epidermal thickening and inflammatory cell infiltration. Excessive proliferation of keratinocytes and resistance to apoptosis lead to thickening of the epidermis. Plasmacytoid dendritic cells are involved in the occurrence of psoriasis mainly by secreting interferon-alpha (IFN-α). IFN-α is a glycoprotein with antiviral, antitumor, and immunomodulatory effects, but its role in psoriasis remains unclear. In this investigation, a mild psoriatic phenotype was observed in mice upon topical application of IFN-α cream, and the inflammation was exacerbated when combined with imiquimod (IMQ). Immunohistochemical analyses demonstrated that IFN-α induces psoriatic inflammation in mice by stimulating phosphorylation of forkhead box O3, consistent with the involvement of this protein in cell proliferation, apoptosis, and inflammation. Our results suggested that topical IFN-α caused psoriatic inflammation and that the psoriatic inflammation was exacerbated by the combination of IFN-α and IMQ, possibly due to the dysfunction of forkhead box O3.

Use of polygenic and clinical risk scores in wide spectrum congenital heart malformations: a diagnostic and therapeutic perspective

Worldwide, congenital heart defects (CHDs) are a leading cause of mortality and morbidity. Globally, the annual prevalence rate of CHDs is about 1.5 million. It is one of the most common life-threatening congenital malformations, with a visible difference between high-income countries (HICs) and developing countries. This difference may be attributed to the diagnostic facilities and interventions.1 Moreover, the use of genetic and clinical risk scores is less studied in this field compared to other diagnostic and therapeutic approaches. Thus, we comprehensively review the available literature on adult and pediatric syndromic or non-syndromic CHDs and propose limitations and future directions in this field. Risk factors for this fatal disease include genetic and environmental factors.2,3 Risk stratification based on prenatal diagnosis with genetic counseling has shown better clinical outcomes. The modified World Health Organization (mWHO) guidelines are among the first proposed for risk stratification based on clinical scores.4 The combination of polygenic risk scores (PRS) and clinical risk evaluation has been adopted in various populations as better diagnostic and therapeutic approaches for various diseases, including coronary artery disease,5 diabetes,6 obesity,7 and cancers.8,9 However, unlike these diseases, polygenic risk scores are rarely used for the genetic diagnosis of CHD patients. The clinical utility of polygenic risk scores for CHDs is still in the early stages and requires validation studies in different cohorts. Incorporating PRS into the clinical setting may improve CHD diagnosis and therapeutic strategies.10 Recently, an initial attempt was made to determine the clinical utility of polygenic risk scores in a large dataset of the European cohort. Data from this study suggested a high potential for PRS in distinguishing between clinical phenotypes (mild, moderate, and severe) of congenital heart malformations.11 Furthermore, this hypothesis was tested in patients with transposition of the great arteries (TGA) to assess the utility of risk stratification after arterial switch operation. The cumulative risk score was computed for single nucleotide polymorphisms (SNPs) that reached the threshold statistical significance of p&lt;1×10−5 in the initial analysis. Combined clinical and polygenic risk scores showed improved risk stratification in mild, moderate, and severe TGA phenotypes.12 Similarly, in another European cohort, the risk allele frequency was higher in the diseased group compared to the control group. However, statistical analysis suggested a non-significant association with p&gt;0.05. Interestingly, combined risk scores constructed for selected SNPs showed a significant association with the disease with a p-value of 0.002. This evidence further supports the hypothesis that the cumulative effect of polymorphisms has better diagnostic and therapeutic efficacy than individual SNPs.13 There are certain limitations to its clinical use. Firstly, social stigma and lack of awareness regarding this disease are major hurdles. Secondly, there is a need to recruit a large number of samples from different populations to validate the clinical utility of PRS. Additionally, a lack of resources in developing countries also contributes to fatal outcomes. We recommend conducting large cohort studies in different ethnic groups to predict better risk associations, develop better therapeutic strategies, and formulate management guidelines.

End-stage ADPKD with a low-frequency PKD1 mosaic variant accelerated by chemoradiotherapy

Autosomal dominant polycystic kidney disease (ADPKD) is commonly caused by PKD1, and mosaic PKD1 variants result in milder phenotypes. We present the case of a 32 year-old male with chronic active Epstein–Barr virus who underwent bone marrow transplantation with chemoradiotherapy at age 9. Despite a low-frequency mosaic splicing PKD1 variant, he developed severe renal cysts and end-stage renal disease in his 30 s. This case highlights how environmental factors may contribute to the genetic predisposition to ADPKD.

Novel Synonymous and Deep Intronic Variants Causing Primary and Secondary Pyruvate Dehydrogenase Complex Deficiency

Pyruvate dehydrogenase complex deficiency (PDCD) is a defect of aerobic carbohydrate metabolism that causes neurological disorders with varying degrees of severity. We report the clinical, biochemical, and molecular findings in patients with primary and secondary PDCD caused by novel atypical genetic variants. Whole-genome sequencing (WGS) identified the synonymous variants c.447A&gt;G, p.(Lys149=) and c.570C&gt;T, p.(Cys190=) in pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1), the deep intronic variants c.1023+2267G&gt;A and c.1023+2302A&gt;G in pyruvate dehydrogenase complex component X (PDHX), and c.185+15054G&gt;A in thiamine pyrophosphokinase (TPK1). Analysis by Sanger and RNA sequencing of cDNA from patient blood and/or cultured fibroblasts showed that the synonymous variants in PDHA1 lead to aberrant splicing and skipping of exons 5 and 5-6 in one of the patients and transcripts lacking exon 6 in the other. The deep intronic variants in PDHX and TPK1 lead to insertion of intronic sequence in the corresponding transcripts. The splice defects in PDHA1 were more pronounced in cultured fibroblasts than in blood. Our findings expand the spectrum of pathogenic variants causing PDCD and highlight the importance of atypical variants leading to aberrant splicing. The severity of the splice defects and resulting biochemical dysfunction varied between tissues, stressing the importance of performing biochemical and transcript analysis in affected tissues. The two males with hemizygous synonymous PDHA1 variants have a mild phenotype and higher PDH enzyme activity than expected, which is consistent with aberrant but leaky splicing with a proportion of the transcripts remaining correctly spliced.