Treating epidermolytic ichthyosis and ichthyosis with confetti with epidermal autografts cultured from revertant skin.

BACKGROUND: No efficient treatment has yet been established for epidermolytic ichthyosis (EI), which is caused by pathogenic variants of KRT1 or KRT10. Patients with ichthyosis with confetti (IWC) have multiple normal-appearing spots, caused by the revertant somatic recombination of pathogenic variants that occurs at each spot independently. Additionally, some patients with EI have large areas of normal skin due to revertant postzygotic mosaicism. OBJECTIVES: To assess the feasibility of transplanting cultured epidermal autografts (CEAs) produced from revertant epidermal keratinocytes in patients with EI and IWC. METHODS: We performed a clinical trial of treatment with CEAs produced from each patient's own revertant epidermal keratinocytes as a proof-of-concept study. This was a single-arm, open, unmasked, uncontrolled, single-assignment, treatment-purpose study. The primary outcome was the percentage area that lacked recurrence of ichthyosis lesions 4 weeks after the final transplant. The secondary outcome was the percentage area lacking recurrence of ichthyosis lesions 24 weeks after the initial transplantation. The trial was registered with the Japan Registry of Clinical Trials (jRCTb041190097). RESULTS: We successfully produced CEAs from genetically confirmed revertant skin from two patients with mosaic EI and from one patient with IWC and confirmed by amplicon sequencing and droplet digital polymerase chain reaction analysis that the CEAs mainly consisted of revertant wild-type cells. Single-cell RNA sequencing analysis confirmed the normal proliferation and safety profiling of CEAs. CEAs were transplanted onto desquamated lesional sites in the patients. Four weeks post-transplantation, the percentage area lacking recurrence of ichthyosis lesions in the three patients was 40%, 100% and 100% respectively, although recurrence of ichthyosis lesions was seen at the site of CEA transplantation in all three patients at 24 weeks post-transplantation. CONCLUSIONS: CEAs from normal skin have the potential to be a safe and local treatment option for EI and IWC.

Epidermolytic ichthyosis is a rare skin condition that causes redness, blistering and thickening of the skin. There is currently no effective treatment for the disease, which is caused by mutations in the genes KRT1 or KRT10. People with a type of the disease called 'ichthyosis with confetti' have many normal-appearing spots that are caused by the natural repair of the gene mutations. Some people with epidermolytic ichthyosis have large areas of healthy skin as a result of genetic mutations having been corrected. In this study, we successfully produced skin grafts from the healthy skin of two patients with epidermolytic ichthyosis and one with 'ichthyosis with confetti'. We confirmed that the skin grafts mainly consisted of repaired skin cells. A technique called 'single-cell RNA sequencing' confirmed the skin cells in the skin grafts behaved like healthy skin cells and that the grafts were safe. Overall, our study findings suggest that skin grafts taken from skin consisting of genetically normal keratinocytes that have undergone self-repair have potential to be a safe treatment option for patients with severe epidermolytic ichthyosis and 'ichthyosis with confetti'.

Updated mutational spectrum and genotype-phenotype correlations in ichthyosis patients with ABCA12 pathogenic variants.

Autosomal recessive congenital ichthyoses (ARCI) is a genetically heterogeneous condition that can be caused by pathogenic variants in at least 12 genes, including ABCA12. ARCI mainly consists of congenital ichthyosiform erythroderma (CIE), lamellar ichthyosis (LI) and harlequin ichthyosis (HI). The objective was to determine previously unreported pathogenic variants in ABCA12 and to update genotype-phenotype correlations for patients with pathogenic ABCA12 variants. Pathogenic variants in ABCA12 were detected using Sanger sequencing or a combination of Sanger sequencing and whole-exome sequencing. To verify the pathogenicity of a previously unreported large deletion and intron variant, cDNA analysis was performed using total RNA extracted from hair roots. Genetic analyses were performed on the patients with CIE, LI, HI and non-congenital ichthyosis with unusual phenotypes (NIUP), and 11 previously unreported ABCA12 variants were identified. Sequencing of cDNA confirmed the aberrant splicing of the variant ABCA12 in the patients with the previously unreported large deletion and intron variant. Our findings expand the phenotype spectrum of ichthyosis patients with ABCA12 pathogenic variants. The present missense variants in ABCA12 are considered to be heterogenous in pathogenicity, and they lead to varying disease severities in patients with ARCI and non-congenital ichthyosis with unusual phenotypes (NIUP).

Cross-sectional nationwide epidemiologic survey on quality of life and treatment efficacy in Japanese patients with congenital ichthyoses.

BACKGROUND: Congenital ichthyoses sometimes present with severe skin symptoms that significantly affect the patient's quality of life (QOL). Symptomatic treatments are the mainstay therapies, and their efficacy is limited and inadequate. OBJECTIVE: To assess the disease severity and QOL in patients with congenital ichthyoses, and to investigate the effectiveness of current treatments. METHODS: We conducted a questionnaire-based Japan-wide epidemiological survey of patients with congenital ichthyosis who received medical care from 1 January 2016-31 December 2020. Effectiveness of past and current treatments was assessed. The outcomes were the physician's assessment, disease severity assessed using the clinical ichthyosis score (CIS), and the disease burden estimated using the Dermatology Life Quality Index (DLQI), the Children's Dermatology Life Quality Index (CDLQI), and the Infants' Dermatitis Quality of Life Index. RESULTS: One hundred patients with 14 ichthyosis subtypes from 47 institutes were included in the final analysis. The CDLQI score showed a positive correlation with CIS (rs = 0.59, p = 0.004), while the DLQI score showed no significant correlation (rs = 0.13, p = 0.33). All existing medications were effective for many patients. Etretinate improved QOL and reduced CIS, but side effects including bone growth retardation were reported. Decreased treatment willingness was observed in patients with very low and very high CIS. CONCLUSION: QOL scores were found to correlate with CIS in children, but not in adults. Considering the adverse events, it is speculated that etretinate is not indicated for children with mild cases. Petrolatum was the most commonly used medication, even in patients who were reluctant to receive treatment.

Generalized Verrucosis on a Background of 3C Syndrome Treated With Subcutaneous IgG Supplementation.

This case report describes a man in his 20s with 3C/Ritscher-Schinzel syndrome who presented to the dermatology department after developing multiple skin lesions.

Ceramide Analysis in Combination With Genetic Testing May Provide a Precise Diagnosis for Self-Healing Collodion Babies.

Self-healing collodion baby (SHCB), also called "self-improving collodion baby", is a rare mild variant of autosomal recessive congenital ichthyosis and is defined as a collodion baby who shows the nearly complete resolution of scaling within the first 3 months to 1 year of life. However, during the neonatal period, it is not easy to distinguish SHCB from other inflammatory forms of autosomal recessive congenital ichthyosis, such as congenital ichthyosiform erythroderma. Here, we report a case study of two Japanese SHCB patients with compound heterozygous mutations, c.235G>T (p.(Glu79∗))/ c.1189C>T (p.(Arg397Cys)) and c.1295A>G (p.(Tyr432Cys))/ c.1138delG (p.(Asp380Thrfs∗3)), in CYP4F22, which encodes cytochrome P450, family 4, subfamily F, polypeptide 22 (CYP4F22). Immunohistochemically, inflammation with the strong expression of IL-17C, IL-36γ, and TNF-α was seen in the skin at birth. CYP4F22 is an ultra-long-chain FA ω-hydroxylase responsible for ω-O-acylceramide (acylceramide) production. Among the epidermal ceramides, acylceramide is a key lipid in maintaining the epidermal permeability barrier function. We found that the levels of ceramides with ω-hydroxy FAs including acylceramides and the levels of protein-bound ceramides were much lower in stratum corneum samples obtained by tape stripping from SHCB patients than in those from their unaffected parents and individuals without SHCB. Additionally, our cell-based enzyme assay revealed that two mutants, p.(Glu79∗) and p.(Arg397Cys), had no enzyme activity. Our findings suggest that genetic testing coupled with noninvasive ceramide analyses using tape-stripped stratum corneum samples might be useful for the early and precise diagnosis of congenital ichthyoses, including SHCB.

Deep Phenotyping of Superficial Epidermolytic Ichthyosis due to a Recurrent Mutation in KRT2.

Superficial epidermolytic ichthyosis (SEI) is an autosomal dominant inherited ichthyosis. SEI is caused by mutations in KRT2 and frequently shows erythroderma and widespread blistering at birth. We report the clinical manifestations of two patients from a Japanese family with SEI caused by a hotspot mutation, p.Glu487Lys, in KRT2. In addition, we summarize previous reports on SEI patients with the identical mutation. One of the two patients had disease onset at the age of 7 months. The other patient's age of onset is unknown, but it was in childhood. Neither of the two patients showed erythroderma. To perform deep phenotyping, we studied the age of onset and the frequency of erythroderma in 34 reported SEI cases with the p.Glu487Lys mutation, including the present cases. Among the cases with sufficient clinical information, 44.4% of the cases that were due to p.Glu487Lys in KRT2 occurred at birth. Erythroderma was observed in 11.1% of the cases with p.Glu487Lys in KRT2.

Autoinflammatory Keratinization Disease With Hepatitis and Autism Reveals Roles for JAK1 Kinase Hyperactivity in Autoinflammation.

Heterozygous mutations in JAK1 which result in JAK-STAT hyperactivity have been implicated in an autosomal dominant disorder that features multi-organ immune dysregulation. This study identifies another previously unreported heterozygous missense JAK1 mutation, H596D, in an individual with a unique autoinflammatory keratinization disease associated with early-onset liver dysfunction and autism. Using CRISPR-Cas9 gene targeting, we generated mice with an identical Jak1 knock-in missense mutation (Jak1H595D/+;I596I/+;Y597Y/+ mice) that recapitulated key aspects of the human phenotype. RNA sequencing of samples isolated from the Jak1H595D/+;I596I/+;Y597Y/+ mice revealed the upregulation of genes associated with the hyperactivation of tyrosine kinases and NF-κB signaling. Interestingly, there was a strong correlation between genes downregulated in Jak1H595D/+;I596I/+;Y597Y/+ mice and those downregulated in the brain of model mice with 22q11.2 deletion syndrome that showed cognitive and behavioral deficits, such as autism spectrum disorders. Our findings expand the phenotypic spectrum of JAK1-associated disease and underscore how JAK1 dysfunction contributes to this autoinflammatory disorder.

Frequent FOXA1-Activating Mutations in Extramammary Paget's Disease.

Extramammary Paget's disease (EMPD) is a neoplastic skin disease of indeterminate origin with an unknown genetic cause. We performed a comprehensive genetic analysis or targeted gene sequencing in 48 patients with EMPD. We identified FOXA1 mutations, a GAS6-FOXA1 fusion gene, and somatic hotspot mutations in the FOXA1 promoter region in 11 of the 48 EMPD patients (11/48, 23%). Additional mutations were identified in PIK3CA (six patients) and in HIST1H2BB, HIST1H2BC, and SMARCB1 (one patient each), but none were found in other frequently mutated genes in cancer. A global gene expression analysis using EMPD clinical samples found the upregulation of PI3 kinase-AKT-mTOR signaling. ABCC11, which is specifically expressed in the apocrine secretory cells and is necessary for their sweat secretion, was upregulated in the EMPD samples. This upregulation suggests that Paget cells originate from apocrine secretory cells. Immunohistochemical staining revealed that FOXA1 expression was prevalent in all of the EMPD samples analyzed and was associated with estrogen receptor expression. Our genetic analysis indicates that EMPD frequently involves FOXA1 mutations. FOXA1 is a transcriptional pioneer factor for the estrogen receptor, and the present results suggest that certain treatments for hormone-dependent cancers could be effective for EMPD.

Reduced stratum corneum acylceramides in autosomal recessive congenital ichthyosis with a NIPAL4 mutation.

BACKGROUND: NIPAL4, encoding the NIPA-like domain containing 4 protein (NIPAL4), is one of the causative genes of autosomal recessive congenital ichthyosis (ARCI). The physiological role of NIPAL4 and the pathogenetic mechanisms of ARCI caused by NIPAL4 mutations remain unclear. OBJECTIVE: To clarify the changes of ceramide components in the lesional stratum corneum (SC) and the gene expression profile in the lesional skin of an ARCI patient with a novel frameshift mutation in NIPAL4. METHODS: We performed ultrastructural and immunohistochemical analyses of the skin. We used RNA sequencing to determine the mRNA expression in the skin of the patient and healthy individuals. We investigated ceramide components using tape stripped SC samples from the patient. RESULTS: mRNA expression profiling in the patient's skin showed significant upregulation of IL-17/TNFα-related genes (IL17C, IL36A, IL36G, S100A7A, S100A9) and psoriasis hallmark genes (VNN3, LCE3D, PLA2G4D), and significant downregulation of lipid-associated genes (GAL, HAO2, FABP7). Ceramide analysis in the patient's SC revealed amounts of CER[NS] with carbon chain-length (C) 32-52 were increased, while amounts of most acylceramide with C66:2 - C72:2 were reduced relatively to those in healthy individuals. After the retinoid treatment, CER[NS] with carbon chains C46-54, CER[EOH] and CER[EOP] increased. CONCLUSION: IL-17C and IL-36 family cytokines might be involved in the pathogenetic process of ARCI with NIPAL4 mutations. Reduced amounts of the acylceramides in the SC are associated with the skin phenotype due to NIPAL4 mutations. Efficacy of the oral retinoid treatment might be due to restored amounts of CER[EOH] and CER[EOP] in the SC.