Structural and Dynamic Analyses of Pathogenic Variants in PIK3R1 Reveal a Shared Mechanism Associated among Cancer, Undergrowth, and Overgrowth Syndromes.

The PI3K enzymes modify phospholipids to regulate cell growth and differentiation. Somatic variants in PI3K are recurrent in cancer and drive a proliferative phenotype. Somatic mosaicism of PIK3R1 and PIK3CA are associated with vascular anomalies and overgrowth syndromes. Germline PIK3R1 variants are associated with varying phenotypes, including immunodeficiency or facial dysmorphism with growth delay, lipoatrophy, and insulin resistance associated with SHORT syndrome. There has been limited study of the molecular mechanism to unify our understanding of how variants in PIK3R1 drive both undergrowth and overgrowth phenotypes. Thus, we compiled genomic variants from cancer and rare vascular anomalies and sought to interpret their effects using an unbiased physics-based simulation approach for the protein complex. We applied molecular dynamics simulations to mechanistically understand how genetic variants affect PIK3R1 and its interactions with PIK3CA. Notably, iSH2 genetic variants associated with undergrowth destabilize molecular interactions with the PIK3CA receptor binding domain in simulations, which is expected to decrease activity. On the other hand, overgrowth and cancer variants lead to loss of inhibitory interactions in simulations, which is expected to increase activity. We find that all disease variants display dysfunctions on either structural characteristics or intermolecular interaction energy. Thus, this comprehensive characterization of novel mosaic somatic variants associated with two opposing phenotypes has mechanistic importance and biomedical relevance and may aid in future therapeutic developments.

Multicenter Study of Long-Term Outcomes and Quality of Life in PHACE Syndrome after Age 10.

OBJECTIVE: To characterize long-term outcomes of PHACE syndrome. STUDY DESIGN: Multicenter study with cross-sectional interviews and chart review of individuals with definite PHACE syndrome ≥10 years of age. Data from charts were collected across multiple PHACE-related topics. Data not available in charts were collected from patients directly. Likert scales were used to assess the impact of specific findings. Patient-Reported Outcomes Measurement Information System (PROMIS) scales were used to assess quality of life domains. RESULTS: A total of 104/153 (68%) individuals contacted participated in the study at a median of 14 years of age (range 10-77 years). There were infantile hemangioma (IH) residua in 94.1%. Approximately one-half had received laser treatment for residual IH, and the majority (89.5%) of participants were satisfied or very satisfied with the appearance. Neurocognitive manifestations were common including headaches/migraines (72.1%), participant-reported learning differences (45.1%), and need for individualized education plans (39.4%). Cerebrovascular arteriopathy was present in 91.3%, with progression identified in 20/68 (29.4%) of those with available follow-up imaging reports. Among these, 6/68 (8.8%) developed moyamoya vasculopathy or progressive stenoocclusion, leading to isolated circulation at or above the level of the circle of Willis. Despite the prevalence of cerebrovascular arteriopathy, the proportion of those with ischemic stroke was low (2/104; 1.9%). PROMIS global health scores were lower than population norms by at least 1 SD. CONCLUSIONS: PHACE syndrome is associated with long-term, mild to severe morbidities including IH residua, headaches, learning differences, and progressive arteriopathy. Primary and specialty follow-up care is critical for PHACE patients into adulthood.

Cutaneous granulomas associated with rubella virus: A clinical review.

Since the initial identification of vaccine-derived rubella virus (RuV) in the cutaneous granulomas of pediatric patients with inborn errors of immunity in 2014, more than 80 cases of RuV granulomas have been reported implicating both vaccine-derived and wild type RuV. Previously thought to arise exclusively in patients with significant immunocompromise, the identification of RuV granulomas in clinically immunocompetent patients adds nuance to our understanding of the interplay between host environment, immune dysregulation, and RuV granuloma formation. This review summarizes the literature on RuV granulomas including clinical and histopathologic features, proposed pathomechanisms supporting granuloma development, and potential therapeutic options. There is no standardized algorithm to guide the workup and diagnosis of suspected RuV granulomas. We highlight the importance of contributing RuV granuloma cases to ongoing Centers for Disease Control and Prevention surveillance efforts to monitor wild type and vaccine-derived RuV transmission. Studies advancing our understanding of RuV granulomas may provide insights into the role of viral infectious agents in granulomatous disease pathogenesis and guide the development of improved therapeutic options.

Presenting characteristics and progression of pediatric-onset morphea: Interim analysis of a prospective registry.

Morphea is a rare fibrosing disorder with a highly variable disease course, which can complicate management. Here, we present a prospective cohort study describing the current treatments used in the management of pediatric-onset morphea and assessing responses to systemic and topical therapies. Most patients demonstrated inactive disease by 1 year, regardless of treatment, though recurrences were common in our cohort overall (39%). Our results support the need for continuous monitoring of all children with morphea following the completion of treatment, including topical treatment, due to high rates of disease relapse.

Early-onset hypertension associated with extensive cutaneous capillary malformations harboring postzygotic variants in GNAQ and GNA11.

BACKGROUND AND OBJECTIVES: Cutaneous capillary malformations (CMs) describe a group of vascular birthmarks with heterogeneous presentations. CMs may present as an isolated finding or with other associations, including glaucoma and leptomeningeal angiomatosis (i.e., Sturge-Weber syndrome) or pigmentary birthmarks (i.e., phakomatosis pigmentovascularis). The use of targeted genetic sequencing has revealed that postzygotic somatic variations in GNAQ and GNA11 at codon 183 are associated with CMs. We report five patients with early-onset hypertension and discuss possible pathogenesis of hypertension. METHODS: Twenty-nine patients with CMs, confirmed GNAQ/11 postzygotic variants, and documented past medical history were identified from a multi-institutional vascular anomalies study. Early-onset hypertension was defined as hypertension before the age of 55 years. Clinical data were reviewed for evidence of hypertension, such as documentation of diagnosis or elevated blood pressure measurements. RESULTS: Five of the 29 patients identified as having GNAQ/11 postzygotic variants had documented early-onset hypertension. Three individuals harbored a GNAQ p.R183Q variant, and two individuals harbored a GNA11 p.R183C variant. All individuals had extensive cutaneous CMs involving the trunk and covering 9%-56% of their body surface area. The median age of hypertension diagnosis was 15 years (range 11-24 years), with three individuals having renal abnormalities on imaging. CONCLUSIONS: Early-onset hypertension is associated with extensive CMs harboring somatic variations in GNAQ/11. Here, we expand on the GNAQ/11 phenotype and hypothesize potential mechanisms driving hypertension. We recommend serial blood pressure measurements in patients with extensive CMs on the trunk and extremities to screen for early-onset hypertension.

Comparison of Work Relative Value Units for Outpatient Pediatric and Adult Dermatology Encounters.

Importance: Dermatologists with specialty training in pediatric dermatology are scarce, which can mean extended wait times and reduced access to care for patients. Lower compensation for pediatric dermatology visits compared with adult visits may affect physician career choice and contribute to workforce shortages. Objective: To evaluate differences in work relative value units (wRVUs) generated by pediatric and adult outpatient dermatology encounters. Design, Setting, and Participants: This cross-sectional study used data from outpatient dermatology encounters at a single-site academic center in Atlanta, Georgia, from September 1, 2016, to March 31, 2020. Encounters with patients younger than 18 years were classified as pediatric, and encounters with those 18 years or older were classified as adult. Encounters with missing data were excluded as were those generating 0 wRVUs, inpatient visits, nursing visits, postoperative encounters, cosmetic procedures, phototherapy visits, and Mohs surgery encounters. Main Outcomes and Measures: Work relative value units generated per encounter type were assessed through multivariable linear regression models adjusted for the potential confounder of sex. Results: The study included 12 989 pediatric dermatology encounters (mean [SD] age, 7.3 [5.2] years; 7586 [58.4%] girls) and 78 057 adult dermatology encounters (mean [SD] age, 54.9 [18.9] years; 45 724 [58.6%] women). Pediatric encounters were associated with 0.23 (95% CI, 0.21-0.25; P < .001) fewer wRVUs than adult encounters after adjusting for sex. In a mediation analysis, biopsies and destruction of premalignant lesions explained 74.1% (95% CI, 69.6%-77.9%; P < .001) of the wRVU difference between pediatric and adult encounters. Conclusions and Relevance: This cross-sectional study found significant differences in wRVUs generated between adult and pediatric dermatology encounters that were largely attributable to biopsies and destruction of premalignant lesions. Policies that increase the value of cognitive services to be on par with procedural care may mitigate wRVU differences and improve reimbursement for pediatric dermatologists.

Development of an artificial intelligence algorithm for the diagnosis of infantile hemangiomas.

Prompt and accurate diagnosis of infantile hemangiomas is essential to prevent potential complications. This can be difficult due to high rates of misdiagnosis and poor access to pediatric dermatologists. In this study, we trained an artificial intelligence algorithm to diagnose infantile hemangiomas based on clinical images. Our algorithm achieved a 91.7% overall accuracy in the diagnosis of facial infantile hemangiomas.

Pernio and early SARS-CoV-2 variants: natural history of a prospective cohort and the role of interferon.

Cases of new-onset pernio and recurrences in our cohort align tightly with trends in mean 7-day COVID-19 positivity in Wisconsin and mean temperature in Madison, Wisconsin by month.

SpotClean adjusts for spot swapping in spatial transcriptomics data.

Spatial transcriptomics is a powerful and widely used approach for profiling the gene expression landscape across a tissue with emerging applications in molecular medicine and tumor diagnostics. Recent spatial transcriptomics experiments utilize slides containing thousands of spots with spot-specific barcodes that bind RNA. Ideally, unique molecular identifiers (UMIs) at a spot measure spot-specific expression, but this is often not the case in practice due to bleed from nearby spots, an artifact we refer to as spot swapping. To improve the power and precision of downstream analyses in spatial transcriptomics experiments, we propose SpotClean, a probabilistic model that adjusts for spot swapping to provide more accurate estimates of gene-specific UMI counts. SpotClean provides substantial improvements in marker gene analyses and in clustering, especially when tissue regions are not easily separated. As demonstrated in multiple studies of cancer, SpotClean improves tumor versus normal tissue delineation and improves tumor burden estimation thus increasing the potential for clinical and diagnostic applications of spatial transcriptomics technologies.

Association of Persistent Rubella Virus With Idiopathic Skin Granulomas in Clinically Immunocompetent Adults.

Importance: Vaccine-derived and wild-type rubella virus (RuV) has been identified within granulomas in patients with inborn errors of immunity, but has not been described in granulomas of healthy adults. Objective: To determine the association between RuV and atypical granulomatous inflammation in immune-competent adults. Design, Setting, and Participants: This case series, conducted in US academic dermatology clinics from January 2019 to January 2021, investigated the presence of RuV in skin specimens using RuV immunofluorescent staining of paraffin-embedded tissue sections, real-time reverse-transcription polymerase chain reaction, whole-genome sequencing with phylogenetic analyses, and cell culture by the US Centers for Disease Control and Prevention. Rubella immunoglobulin G, immunoglobulin M enzyme-linked immunoassay, and viral neutralization assays were performed for the sera of immunocompetent individuals with treatment refractory cutaneous granulomas and histopathology demonstrating atypical palisaded and necrotizing granulomas. Clinical immune evaluation was performed. Main Outcomes and Measures: Identification, genotyping, and culture of vaccine-derived and wild-type RuV within granulomatous dermatitis of otherwise clinically immune competent adults. Results: Of the 4 total immunocompetent participants, 3 (75%) were women, and the mean (range) age was 61.5 (49.0-73.0) years. The RuV capsid protein was detected by immunohistochemistry in cutaneous granulomas. The presence of RuV RNA was confirmed by real-time reverse-transcription polymerase chain reaction in fresh-frozen skin biopsies and whole-genome sequencing. Phylogenetic analysis of the RuV sequences showed vaccine-derived RuV in 3 cases and wild-type RuV in 1. Live RuV was recovered from the affected skin in 2 participants. Immunology workup results demonstrated no primary immune deficiencies. Conclusions and Relevance: The case series study results suggest that RuV (vaccine derived and wild type) can persist for years in cutaneous granulomas in clinically immunocompetent adults and is associated with atypical (palisaded and necrotizing type) chronic cutaneous granulomas. These findings represent a potential paradigm shift in the evaluation, workup, and management of atypical granulomatous dermatitis and raises questions regarding the potential transmissibility of persistent live RuV.

A global effort to dissect the human genetic basis of resistance to SARS-CoV-2 infection.

SARS-CoV-2 infections display tremendous interindividual variability, ranging from asymptomatic infections to life-threatening disease. Inborn errors of, and autoantibodies directed against, type I interferons (IFNs) account for about 20% of critical COVID-19 cases among SARS-CoV-2-infected individuals. By contrast, the genetic and immunological determinants of resistance to infection per se remain unknown. Following the discovery that autosomal recessive deficiency in the DARC chemokine receptor confers resistance to Plasmodium vivax, autosomal recessive deficiencies of chemokine receptor 5 (CCR5) and the enzyme FUT2 were shown to underlie resistance to HIV-1 and noroviruses, respectively. Along the same lines, we propose a strategy for identifying, recruiting, and genetically analyzing individuals who are naturally resistant to SARS-CoV-2 infection.

From Your Nose to Your Toes: A Review of Severe Acute Respiratory Syndrome Coronavirus 2 Pandemic‒Associated Pernio.

Despite thousands of reported patients with pandemic-associated pernio, low rates of seroconversion and PCR positivity have defied causative linkage to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pernio in uninfected children is associated with monogenic disorders of excessive IFN-1 immunity, whereas severe COVID-19 pneumonia can result from insufficient IFN-1. Moreover, SARS-CoV-2 spike protein and robust IFN-1 response are seen in the skin of patients with pandemic-associated pernio, suggesting an excessive innate immune skin response to SARS-CoV-2. Understanding the pathophysiology of this phenomenon may elucidate the host mechanisms that drive a resilient immune response to SARS-CoV-2 and could produce relevant therapeutic targets.

Mapping of Segmental and Partial Segmental Infantile Hemangiomas of the Face and Scalp.

IMPORTANCE: Recognizing segmental infantile hemangioma (IH) patterns is important for risk stratification and provides clues to pathogenesis. Previously, segmental hemangiomas were mapped to 4 facial regions, 3 corresponding to known facial metameres. OBJECTIVES: To refine existing maps of facial segmental IHs, examine so-called indeterminate hemangiomas as they relate to known segmental patterns, and define a novel pattern of segmental scalp hemangiomas. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study was conducted at 4 pediatric dermatology centers (University of California, San Francisco; Indiana University; Medical College of Wisconsin; and Northwestern University/Ann & Robert H. Lurie Children's Hospital of Chicago) using photographic archives of patients younger than 12 years with segmental and indeterminate hemangiomas on the face and scalp. Clinical images were used to map hemangioma distribution onto standardized facial templates. Heat map densiometry identified recurrent patterns that were compared with previously published patterns of facial segmental hemangiomas. Patterns of indeterminate hemangiomas were compared with those of segmental hemangiomas. Data collection took place in 2017, and analysis took place from 2017 to 2019. MAIN OUTCOMES AND MEASURES: Distribution and patterning of segmental and indeterminate IHs of the face and scalp. RESULTS: A total of 549 IHs were mapped. The borders of the frontotemporal (S1) and frontonasal (S4) segments agreed with previous segmental maps; however, the maxillary (S2) and mandibular (S3) segment borders differed with respect to the preauricular skin. In contrast with previous reports, preauricular skin segregated with the mandibular (S3) rather than the maxillary (S2) segment. Indeterminate hemangiomas occurred within and respected the same borders as segmental hemangiomas. Hemangiomas on the lateral scalp commonly occurred in a C shape extending from the posterior auricular region. CONCLUSIONS AND RELEVANCE: This cohort study provides an updated map of facial segmental IHs with redefined maxillary (S2) and mandibular (S3) segment borders. It provides evidence that indeterminate hemangiomas are partial segmental hemangiomas respecting anatomic boundaries of their larger segmental counterparts. A newly recognized C-shaped pattern of segmental scalp hemangioma is reported.

Novel findings and expansion of phenotype in a mosaic RASopathy caused by somatic KRAS variants.

Mosaic KRAS variants and other RASopathy genes cause oculoectodermal, encephalo-cranio-cutaneous lipomatosis, and Schimmelpenning-Feuerstein-Mims syndromes, and a spectrum of vascular malformations, overgrowth and other associated anomalies, the latter of which are only recently being characterized. We describe eight individuals in total (six unreported cases and two previously reported cases) with somatic KRAS variants and variably associated features. Given the findings of somatic overgrowth (in seven individuals) and vascular or lymphatic malformations (in eight individuals), we suggest mosaic RASopathies (mosaic KRAS variants) be considered in the differential diagnosis for individuals presenting with asymmetric overgrowth and lymphatic or vascular anomalies. We expand the association with embryonal tumors, including the third report of embryonal rhabdomyosarcoma, as well as novel findings of Wilms tumor and nephroblastomatosis in two individuals. Rare or novel findings in our series include the presence of epilepsy, polycystic kidneys, and T-cell deficiency in one individual, and multifocal lytic bone lesions in two individuals. Finally, we describe the first use of targeted therapy with a MEK inhibitor for an individual with a mosaic KRAS variant. The purposes of this report are to expand the phenotypic spectrum of mosaic KRAS-related disorders, and to propose possible mechanisms of pathogenesis, and surveillance of its associated findings.

Somatic PIK3R1 variation as a cause of vascular malformations and overgrowth.

PURPOSE: Somatic activating variants in the PI3K-AKT pathway cause vascular malformations with and without overgrowth. We previously reported an individual with capillary and lymphatic malformation harboring a pathogenic somatic variant in PIK3R1, which encodes three PI3K complex regulatory subunits. Here, we investigate PIK3R1 in a large cohort with vascular anomalies and identify an additional 16 individuals with somatic mosaic variants in PIK3R1. METHODS: Affected tissue from individuals with vascular lesions and overgrowth recruited from a multisite collaborative network was studied. Next-generation sequencing targeting coding regions of cell-signaling and cancer-associated genes was performed followed by assessment of variant pathogenicity. RESULTS: The phenotypic and variant spectrum associated with somatic variation in PIK3R1 is reported herein. Variants occurred in the inter-SH2 or N-terminal SH2 domains of all three PIK3R1 protein products. Phenotypic features overlapped those of the PIK3CA-related overgrowth spectrum (PROS). These overlapping features included mixed vascular malformations, sandal toe gap deformity with macrodactyly, lymphatic malformations, venous ectasias, and overgrowth of soft tissue or bone. CONCLUSION: Somatic PIK3R1 variants sharing attributes with cancer-associated variants cause complex vascular malformations and overgrowth. The PIK3R1-associated phenotypic spectrum overlaps with PROS. These data extend understanding of the diverse phenotypic spectrum attributable to genetic variation in the PI3K-AKT pathway.

Light-based treatment of pediatric port-wine birthmarks.

Port-wine birthmarks (PWBs) are progressive vascular malformations with significant disfigurement and psychosocial morbidity; early light-based treatment has shown improved outcomes in the pediatric population. Somatic mosaic mutations underly the progressive nature of PWBs and explain the significant differences in response and heterogeneity of vessel architecture in the pediatric population when compared to the adult cohort. Here, we summarize a review of pediatric specific literature on the various light-based treatment modalities, including pulsed dye laser, near-infrared lasers, and intense pulsed light, providing the various indications, tips, advantages, and disadvantages for the pediatric dermatologist.