Blepharophimosis with intellectual disability and Helsmoortel-Van Der Aa Syndrome share episignature and phenotype.

Blepharophimosis with intellectual disability (BIS) is a recently recognized disorder distinct from Nicolaides-Baraister syndrome that presents with distinct facial features of blepharophimosis, developmental delay, and intellectual disability. BIS is caused by pathogenic variants in SMARCA2, that encodes the catalytic subunit of the superfamily II helicase group of the BRG1 and BRM-associated factors (BAF) forming the BAF complex, a chromatin remodeling complex involved in transcriptional regulation. Individuals bearing variants within the bipartite nuclear localization (BNL) signal domain of ADNP present with the neurodevelopmental disorder known as Helsmoortel-Van Der Aa Syndrome (HVDAS). Distinct DNA methylation profiles referred to as episignatures have been reported in HVDAS and BAF complex disorders. Due to molecular interactions between ADNP and BAF complex, and an overlapping craniofacial phenotype with narrowing of the palpebral fissures in a subset of patients with HVDAS and BIS, we hypothesized the possibility of a common phenotype-specific episignature. A distinct episignature was shared by 15 individuals with BIS-causing SMARCA2 pathogenic variants and 12 individuals with class II HVDAS caused by truncating pathogenic ADNP variants. This represents first evidence of a sensitive phenotype-specific episignature biomarker shared across distinct genetic conditions that also exhibit unique gene-specific episignatures.

Reciprocal chromosome translocation t(3;4)(q27;q31.2) with deletion of 3q27 and reduced FBXW7 expression in a patient with developmental delay, hypotonia, and seizures.

Reciprocal chromosomal translocation is one of genomic variations. When cytogenetically de novo reciprocal translocations are identified in patients with some clinical manifestations, the genes in the breakpoints are considered to be related to the clinical features. In this study, we encountered a patient with severe developmental delay, intractable epilepsy, growth failure, distinctive features, and skeletal manifestations. Conventional karyotyping revealed a de novo translocation described as 46,XY,t(3;4)(q27;q31.2). Chromosomal microarray testing detected a 1.25-Mb microdeletion at 3q27.3q28. Although the skeletal manifestations may have been affected by this deletion, the neurological features of this patient were severe and could not be fully explained by this deletion. Since no genomic copy number aberration was detected on chromosome 4, long-read whole-genome sequencing analysis was performed and a precise breakpoint was confirmed. A 460-bp deletion was detected between the two breakpoints; however, no gene was disrupted. FBXW7, the gene responsible for developmental delay, hypotonia, and impaired language, is in the 0.5-Mb telomeric region. Most of the patient's clinical features were considered consistent with symptoms of FBXW7-related disorders, but were more severe. FBXW7 expression in the immortalized lymphoblasts of the patient was reduced compared to that in controls. Based on these findings, we suspect that FBXW7 is affected by downstream position effects of chromosomal translocations. The severe neurological features of the patient may have been affected not only by the 3q27-q28 deletion but also by impaired expression of FBXW7 derived from the breakage of chromosome 4.

Preimplantation genetic testing using comprehensive genomic copy number analysis is beneficial for balanced translocation carriers.

Balanced chromosomal translocation is one of chromosomal variations. Carriers of balanced chromosomal translocations have an increased risk of spontaneous miscarriage. To avoid the risk, preimplantation genetic testing (PGT) using comprehensive genomic copy number analysis has been developed. This study aimed to verify whether and how embryos from couples in which one partner is a balanced translocation carrier have a higher ratio of chromosomal abnormalities. A total of 894 biopsied trophectoderms (TEs) were obtained from 130 couples in which one partner was a balanced translocation carrier (Robertsonian translocation, reciprocal translocation, or intrachromosomal inversion) and grouped as PGT-SR. Conversely, 3269 TEs from 697 couples who experienced recurrent implantation failure or recurrent pregnancy loss were included in the PGT-A group. The transferable blastocyst ratio was significantly lower in the PGT-SR group, even when bias related to the sample number and patient age was corrected. Subgroup analysis of the PGT-SR group revealed that the transferable blastocyst ratio was higher in the Robertsonian translocation group. Because the PGT-SR group had a higher proportion of untransferable embryos than the PGT-A group, PGT using comprehensive genomic copy number analysis was more beneficial for balanced translocation carriers than for infertility patients without chromosomal translocations. The frequencies of de novo aneuploidies were further analyzed, and the frequency in the PGT-SR group was lower than that in the PGT-A group. Therefore, we could not confirm the existence of interchromosomal effects in this study.

Congenital anemia reveals distinct targeting mechanisms for master transcription factor GATA1.

Master regulators, such as the hematopoietic transcription factor (TF) GATA1, play an essential role in orchestrating lineage commitment and differentiation. However, the precise mechanisms by which such TFs regulate transcription through interactions with specific cis-regulatory elements remain incompletely understood. Here, we describe a form of congenital hemolytic anemia caused by missense mutations in an intrinsically disordered region of GATA1, with a poorly understood role in transcriptional regulation. Through integrative functional approaches, we demonstrate that these mutations perturb GATA1 transcriptional activity by partially impairing nuclear localization and selectively altering precise chromatin occupancy by GATA1. These alterations in chromatin occupancy and concordant chromatin accessibility changes alter faithful gene expression, with failure to both effectively silence and activate select genes necessary for effective terminal red cell production. We demonstrate how disease-causing mutations can reveal regulatory mechanisms that enable the faithful genomic targeting of master TFs during cellular differentiation.

Local neutrophil and eosinophil extracellular traps formation in pyodermatitis pyostomatitis vegetans.

Pyodermatitis pyostomatitis vegetans is a rare inflammatory condition, affecting the skin and/or mucous membrane. Some cases include both skin and mucous involvement, whereas others develop either skin or mucous lesions only. The typically affected areas are the scalp, face, trunk and extremities, including the flexural areas and umbilicus. Clinical features show erosive granulomatous plaques, keratotic plaques with overlying crusts and pustular lesions. Among mucous lesions, oral mucosa is most frequently involved, and gingival erythema, shallow erosions, cobblestone-like papules on the buccal mucosa or upper hard palate of the oral cavity are also observed. Some of the lesions assume a 'snail track' appearance. Although there are several similarities between pyodermatitis pyostomatitis vegetans and other diseases, that is pyoderma gangrenosum, pemphigus vegetans and pemphigoid vegetans, the histopathological features of pyodermatitis pyostomatitis vegetans are unique in that epidermal hyperplasia, focal acantholysis and dense inflammatory infiltrates with intraepidermal and subepidermal eosinophilic microabscesses are observed. Direct immunofluorescence findings are principally negative. Activated neutrophils are supposed to play an important role in the pathogenesis of pyodermatitis pyostomatitis vegetans. The expression of IL-36 and neutrophil extracellular traps (NETs) was observed in the lesional skin, and additionally, eosinophil extracellular traps (EETs) was detected in pyodermatitis pyostomatitis vegetans. A possible pathogenic role of NETs and EETs in the innate immunity and autoinflammatory aspects of pyodermatitis pyostomatitis vegetans was discussed.

A core domain set for pyoderma gangrenosum trial outcomes: an international eDelphi and consensus study from the UPGRADE initiative.

BACKGROUND: Pyoderma gangrenosum (PG) is a rare ulcerative skin condition with no current standardized outcomes or outcome measures. With a rich investigational therapeutic pipeline, standardization of outcomes and improvement of data quality and interpretability will promote the appropriate and consistent evaluation of potential new therapies. Core outcome sets (COS) are agreed, standardized sets of outcomes that represent the minimum that should be measured and reported in all clinical trials of a specific condition. OBJECTIVES: To identify and reach a consensus on which domains (what to be measured) should be included in the Understanding Pyoderma Gangrenosum: Review and Analysis of Disease Effects (UPGRADE) core domain set for clinical trials in PG. METHODS: Collaborative discussions between patients and PG experts, and a systematic review of the literature identified items and prospective domains. A three-round international eDelphi exercise was performed to prioritize the domains and refine the provisional items (consensus: ≥ 70% of participants rating a domain as 'extremely important' and < 15% of participants voting 'not important'), followed by an international meeting to reach consensus on the core domain set (consensus: < 30% disagreement). Item-generation discussions and consensus meetings were hosted via online videoconferences. The eDelphi exercise and consensus voting were performed using Qualtrics survey software. Participants were adults with PG, healthcare professionals, researchers and industry representatives. RESULTS: Collaborative discussions and systematic reviews yielded 115 items, which were distilled into 15 prospective domains. The eDelphi exercise removed the three lowest-priority domains ('laboratory tests', 'treatment costs' and 'disease impact on family') and ranked 'pain', 'quality of life' and 'physical symptoms' as the highest-priority prospective domains. Consensus was reached on the domains of 'pain', 'quality of life' and 'clinical signs'. The domain of 'disease course/disease progression' narrowly failed to reach consensus for inclusion in the core set (32% of participants voted 'no'). Refinement of this domain definition will be required and presented for consideration at future consensus meetings. CONCLUSIONS: The UPGRADE core domain set for clinical trials in PG has been agreed by international multistakeholder consensus. Future work will develop and/or select outcome measurement instruments for these domains to establish a COS.

Clonal Hematopoiesis Without Malignant Transformation Lasting Over 2 Years in a 9-Year-old Boy, Following Treatment for Acute Lymphocytic Leukemia.

Children with acute lymphocytic leukemia rarely develop secondary hematological neoplasms. A 5-year-old boy was diagnosed with standard-risk precursor B-cell acute lymphocytic leukemia. The patient exhibited aberrant chromosomal changes in the bone marrow at 6 months postchemotherapy: 46,XY,der(6) t(1;6)(q12;p22) dup(6)(p22p12)[15]. Clinically, the patient has sustained complete remission and has not developed myeloid malignancy over the subsequent period (27 mo). The cytogenetic aberration was observed in 11% of CD34+ cells isolated from the bone marrow. We infer that the abnormal clone acquires self-renewal potency, differentiation, and growth advantage. Further long-term observation is needed to determine the nature of this cytogenetic aberration.

Pyodermatitis vegetans confined to the umbilicus: Report of 2 cases.

Pyodermatitis pyostomatitis vegetans is a rare variant of neutrophilic disorders, affecting the intertriginous areas such as axilla and groin, umbilicus, as well as the oral mucosa. We herein describe 2 female patients, in both of whom the umbilicus was restrictedly involved.

Impaired neuronal activity and differential gene expression in STXBP1 encephalopathy patient iPSC-derived GABAergic neurons.

Syntaxin-binding protein 1 (STXBP1; also called MUNC18-1), encoded by STXBP1, is an essential component of the molecular machinery that controls synaptic vesicle docking and fusion. De novo pathogenic variants of STXBP1 cause a complex set of neurological disturbances, namely STXBP1 encephalopathy (STXBP1-E) that includes epilepsy, neurodevelopmental disorders and neurodegeneration. Several animal studies have suggested the contribution of GABAergic dysfunction in STXBP1-E pathogenesis. However, the pathophysiological changes in GABAergic neurons of these patients are still poorly understood. Here, we exclusively generated GABAergic neurons from STXBP1-E patient-derived induced pluripotent stem cells (iPSCs) by transient expression of the transcription factors ASCL1 and DLX2. We also generated CRISPR/Cas9-edited isogenic iPSC-derived GABAergic (iPSC GABA) neurons as controls. We demonstrated that the reduction in STXBP1 protein levels in patient-derived iPSC GABA neurons was slight (approximately 20%) compared to the control neurons, despite a 50% reduction in STXBP1 mRNA levels. Using a microelectrode array-based assay, we found that patient-derived iPSC GABA neurons exhibited dysfunctional maturation with reduced numbers of spontaneous spikes and bursts. These findings reinforce the idea that GABAergic dysfunction is a crucial contributor to STXBP1-E pathogenesis. Moreover, gene expression analysis revealed specific dysregulation of genes previously implicated in epilepsy, neurodevelopment and neurodegeneration in patient-derived iPSC GABA neurons, namely KCNH1, KCNH5, CNN3, RASGRF1, SEMA3A, SIAH3 and INPP5F. Thus, our study provides new insights for understanding the biological processes underlying the widespread neuropathological features of STXBP1-E.

Identification of small-sized intrachromosomal segments at the ends of INV-DUP-DEL patterns.

The mechanism of chromosomal rearrangement associated with inverted-duplication-deletion (INV-DUP-DEL) pattern formation has been investigated by many researchers, and several possible mechanisms have been proposed. Currently, fold-back and subsequent dicentric chromosome formation has been established as non-recurrent INV-DUP-DEL pattern formation mechanisms. In the present study, we analyzed the breakpoint junctions of INV-DUP-DEL patterns in five patients using long-read whole-genome sequencing and detected 2.2-6.1 kb copy-neutral regions in all five patients. At the end of the INV-DUP-DEL, two patients exhibited chromosomal translocations, which are recognized as telomere capture, and one patient showed direct telomere healing. The remaining two patients had additional small-sized intrachromosomal segments at the end of the derivative chromosomes. These findings have not been previously reported but they may only be explained by the presence of telomere capture breakage. Further investigations are required to better understand the mechanisms underlying this finding.

Neutrophil extracellular traps formation in the lesional skin of various types of pyoderma gangrenosum.

Pyoderma gangrenosum (PG) is a chronic neutrophilic disorder characterized by recurrent painful ulcers. Aseptic inflammation by neutrophils plays an essential role, and neutrophil extracellular traps (NETs) formation can contribute to the pathogenesis of PG. Seventy-five patients were diagnosed as having PG in our department, among which 58 ulcerative, 4 bullous, 3 pustular and 10 vegetative type. We examined the 20 skin biopsy specimens (11 ulcerative, 3 bullous, 2 pustular and 4 vegetative type), and local NETs formation in various types of PG was compared among each type. The biopsied specimens were double labelled for myeloperoxidase, citrullinated histone H3. Immunofluorescent images indicated that the histopathologic location and depth of NETs formation in PG varied by the clinical subtypes. In ulcerative PG, NETs formation was observed in the upper to deep dermis. In bullous PG, NETs formation was mainly observed in the epidermis. Pustular type showed NETs formation in the epidermis near the pustules, and in vegetative type, showed NETs formation mainly in the upper dermis. These results indicate that NETting neutrophils play an important role in the pathogenesis of various forms of PG, although the location and depth of NETs formation in the skin lesion of PG differ depending on each type. Further studies are necessary to examine what factors identify different clinical features of PG.

A Novel de novo KIF1A Mutation in a Patient with Ataxia, Intellectual Disability and Mild Foot Deformity.

Early-onset ataxias are often difficult to diagnose due to the genetic and phenotypic heterogeneity of patients. Whole exome sequencing (WES) is a powerful method for determining causative mutations of early-onset ataxias. We report a case in which a novel de novo KIF1A mutation was identified in a patient with ataxia, intellectual disability and mild foot deformity.A patient presented with sporadic forms of ataxia with mild foot deformity, intellectual disability, peripheral neuropathy, pyramidal signs, and orthostatic hypotension. WES was used to identify a novel de novo mutation in KIF1A, a known causative gene of neurodegeneration and spasticity with or without cerebellar atrophy or cortical visual impairment syndrome (NESCAVS).We report a novel phenotype of NESCAVS that is associated with a novel de novo missense mutation in KIF1A, which provides valuable information for the diagnosis of NESCAVS even in the era of WES. Early rehabilitation of patients with NESCAVS may prevent symptom worsening and improve the disease course.

Breakpoint analysis for cytogenetically balanced translocation revealed unexpected complex structural abnormalities and suggested the position effect for MEF2C.

Many disease-causing genes have been identified by determining the breakpoints of balanced chromosomal translocations. Recent progress in genomic analysis has accelerated the analysis of chromosomal translocation-breakpoints at the nucleotide level. Using a long-read whole-genome sequence, we analyzed the breakpoints of the cytogenetically balanced chromosomal translocation t(5;15)(q21;26.3), which was confirmed to be of de novo origin, in a patient with a neurodevelopmental disorder. The results showed complex rearrangements with seven fragments consisting of five breakpoint-junctions (BJs). Four of the five BJs showed microhomologies of 1-3-bp, and only one BJ displayed a signature of blunt-end ligation, indicating chromothripsis as the underlying mechanism. Although the BJs did not disrupt any disease-causing gene, the clinical features of the patient were compatible with MEF2C haploinsufficiency syndrome. Complex rearrangements were located approximately 2.5-Mb downstream of MEF2C. Therefore, position effects were considered the mechanism of the occurrence of MEF2C haploinsufficiency syndrome.

Interstitial microdeletions of 3q26.2q26.31 in two patients with neurodevelopmental delay and distinctive features.

Interstitial microdeletions in the long arm of chromosome 3 are rare. In this study, we identified two patients with approximately 5-Mb overlapping deletions in the 3q26.2q26.31 region. Both patients showed neurodevelopmental delays, congenital heart defects, and distinctive facial features. One of them showed growth deficiency and brain abnormalities, as shown on a magnetic resonance imaging scan. Haploinsufficiency of NLGN1 and FNDC3B present in the common deletion region was considered to be responsible for neurodevelopmental delay and the distinctive features, respectively. The possibility of unmasked variants in PLD1 was considered and analyzed, but no possible pathogenic variant was found, and the mechanism of the congenital heart defects observed in the patients is unknown. Because 3q26.2q26.31 deletions are rare, more information is required to establish genotype-phenotype correlations associated with microdeletions in this region.

Long-read sequence analysis for clustered genomic copy number aberrations revealed architectures of intricately intertwined rearrangements.

Most chromosomal aberrations revealed by chromosomal microarray testing (CMA) are simple; however, very complex chromosomal structural rearrangements can also be found. Although the mechanism of structural rearrangements has been gradually revealed, not all mechanisms have been elucidated. We analyzed the breakpoint-junctions (BJs) of two or more clustered copy number variations (CNVs) in the same chromosome arms to understand their conformation and the mechanism of complex structural rearrangements. Combining CMA with long-read whole-genome sequencing (WGS) analysis, we successfully determined all BJs for the clustered CNVs identified in four patients. Multiple CNVs were intricately intertwined with each other, and clustered CNVs in four patients were involved in global complex chromosomal rearrangements. The BJs of two clustered deletions identified in two patients showed microhomologies, and their characteristics were explained by chromothripsis. In contrast, the BJs in the other two patients, who showed clustered deletions and duplications, consisted of blunt-end and nontemplated insertions. These findings could be explained only by alternative nonhomologous end-joining, a mechanism related to polymerase theta. All the patients had at least one inverted segment. Three patients showed cryptic aberrations involving a disruption and a deletion/duplication, which were not detected by CMA but were first identified by WGS. This result suggested that complex rearrangements should be considered if clustered CNVs are observed in the same chromosome arms. Because CMA has potential limitations in genotype-phenotype correlation analysis, a more detailed analysis by whole genome examination is recommended in cases of suspected complex structural aberrations.

Craniofacial and dental characteristics of three Japanese individuals with genetically diagnosed SATB2-associated syndrome.

Craniofacial defects are one of the most frequent phenotypes in syndromic diseases. More than 30% of syndromic diseases are associated with craniofacial defects, which are important for the precise diagnosis of systemic diseases. Special AT-rich sequence-binding protein 2 (SATB2)-associated syndrome (SAS) is a rare syndromic disease associated with a wide variety of phenotypes, including intellectual disability and craniofacial defects. Among them, dental anomalies are the most frequently observed phenotype and thus becomes an important diagnostic criterion for SAS. In this report, we demonstrate three Japanese cases of genetically diagnosed SAS with detailed craniofacial phenotypes. The cases showed multiple dental problems, which have been previously reported to be linked to SAS, including abnormal crown morphologies and pulp stones. One case showed a characteristic enamel pearl at the root furcation. These phenotypes add new insights for differentiating SAS from other disorders.

Factors influencing the decision to introduce alternative nutrition in patients with Duchenne muscular dystrophy.

INTRODUCTION/AIMS: Nutritional management of adults with Duchenne muscular dystrophy (DMD) is an important clinical issue. However, it is not clear which dysphagia-related factors should prompt introduction of alternative nutrition (AN). We aimed to determine which patients with DMD were introduced to AN. METHODS: This retrospective study included 56 patients with DMD (median age, 23.5 years). They were divided into patients able to continue oral feeding (OF) and those introduced to AN. Body weight, frequency of ventilator use, daily meals, history of steroid treatment, results of videofluoroscopic examination of swallowing (VF), and awareness of dysphagia were evaluated. RESULTS: Of 56 patients, 19 were in the AN group. After AN introduction, 93% of the patients continued oral intake. The proportion of patients who consumed chopped and liquid diets was higher, and body weight was lower, in the AN than in the OF group. There were no significant differences in age, upper limb function of feeding, frequency of ventilator use, or history of steroid therapy between the two groups. The frequencies of aspiration and residue in the pyriform sinus in VF were higher in the AN group than in the OF group. Decision-tree analysis showed that food form and subjective difficulty swallowing solid foods were the most important factors affecting the decision-making for AN. DISCUSSION: Patients with DMD who had difficulty eating solid foods were started on AN because they were unable to maintain their weight. These findings provide information for future longitudinal studies to assess the value of AN.

Precise clinicopathologic findings for application of genetic testing in pediatric kidney transplant recipients with focal segmental glomerulosclerosis/steroid-resistant nephrotic syndrome.

BACKGROUND: Establishing a molecular genetic diagnosis of focal segmental glomerulosclerosis (FSGS)/steroid-resistant nephrotic syndrome (SRNS) can be useful for predicting post-transplant recurrence. Monogenic causes are reportedly present in approximately 20-30% of patients with FSGS/SRNS. However, the characteristics of patients who are likely to have a monogenic cause remain to be determined. METHODS: Pediatric recipients with SRNS and/or biopsy-proven FSGS who underwent their first kidney transplantation at our center between 1999 and 2019 were analyzed. Patients with secondary FSGS/SRNS were excluded. The recipients were divided into three groups: familial/syndromic, presumed primary, and undetermined FSGS/SRNS. Patients who met all of the following criteria were categorized as having presumed primary FSGS/SRNS: (i) nephrotic syndrome, (ii) complete or partial remission with initial steroid therapy and/or additional immunosuppressive therapies, and (iii) diffuse foot process effacement on electron microscopy in the native kidney biopsy. All patients underwent genetic testing using next-generation sequencing. RESULTS: Twenty-four patients from 23 families were analyzed in this study. Pathogenic or likely pathogenic variants in FSGS/SRNS-related genes were identified in four of four families, zero of eight families, and 10 of 11 families with familial/syndromic, presumed primary, and undetermined FSGS/SRNS, respectively. Post-transplant recurrence only occurred in patients with presumed primary FSGS/SRNS. CONCLUSIONS: Our systematic approach based on precise clinicopathological findings including nephrotic syndrome, treatment responses, and diffuse foot process effacement might be useful to differentiate pediatric kidney transplant recipients with FSGS/SRNS who are likely to have a monogenic cause from patients who are not, and to predict post-transplant recurrence. A higher resolution version of the Graphical abstract is available as Supplementary information.

Immune escape mechanism behind resistance to anti-PD-1 therapy in gastrointestinal tract metastasis in malignant melanoma patients with multiple metastases.

Immunotherapy targeting the PD-1 axis has recently become a standard treatment for patients with malignant melanoma. However, approximately 25% of reported malignant melanoma patients who initially responded to immunotherapy with anti-PD-1 mAb had progressive disease, and the immune escape mechanism behind resistance to anti-PD-1 therapy is not yet fully understood in the clinical setting. In the present study, we included four malignant melanoma patients, in whom multiple metastases other than gastrointestinal tract metastasis had disappeared or were controlled under multidisciplinary treatment that included anti-PD-1 therapy. Using IHC, we evaluated the immune status of surgically resected specimens of gastrointestinal tract metastases as acquired resistant lesion to anti-PD-1 therapy. We herein report that the down-regulated expression of HLA class I and up-regulated expression of inhibitory immune checkpoint ligands, CD155 (ligand for T cell immunoglobulin and ITIM domain, TIGIT) and carcinoembryonic antigen-related adhesion molecule-1 (ligand for TIM-3), were observed on the tumor cells in the metastatic gastrointestinal tract tumors. Moreover, our results also suggest that stromal TGF-ß may be related to this down-regulation of HLA class I expression on the tumor cells. In conclusion, it is likely that the down-regulated expression of HLA class I and additional expression of inhibitory immune checkpoint ligands other than PD-L1 on the tumor cells were acquired in the gastrointestinal tract metastasis during anti-PD-1 therapy in the malignant melanoma patients.

Severe de novo pustular psoriasiform immune-related adverse event associated with nivolumab treatment for metastatic esophageal adenocarcinoma.

Breakthrough targeted therapies have produced significant improvements in survival for cancer patients, but have a propensity to cause cutaneous immune-related adverse events (irAEs). Psoriasiform irAEs, representing about 4% of dermatologic toxicities associated with immune checkpoint inhibitor (ICI) therapy, are usually mild, occur in older patients and present as an exacerbation of existing psoriasis after several doses of ICI therapy. We report a case of a 58-year-old woman with metastatic esophageal adenocarcinoma and no prior history of psoriasis who developed a pustular psoriasiform irAE, beginning 3 days after initiation of nivolumab and progressing to confluent erythroderma with pustules over 2 weeks despite topical steroid use. She had concurrent acrodermatitis enteropathica, clinically diagnosed and confirmed with a low serum zinc level, that improved with supplementation. Her psoriasiform irAE was refractory to systemic steroids and acitretin, prompting discontinuation of nivolumab and treatment with ustekinumab and concomitant slow taper of acitretin and prednisone. Pustular psoriasiform irAE is a rare but severe dermatologic toxicity resulting from ICI therapy. Given the diverse morphologic types of cutaneous irAEs that can occur during ICI therapy, a clinical and histopathologic examination of dermatologic toxicities is critical to identify patients who may benefit from biologic therapy.