Hailey-Hailey Disease Successfully Treated With Adalimumab: A Case Series.

Hailey-Hailey disease is an autosomal dominant disorder caused by a mutation in the ATP2C1 gene and characterized by recurrent blisters, erosions, and crust in intertriginous areas. Currently, there are no curative treatments for Hailey-Hailey disease, and therapeutic strategies are focused on controlling skin microbial colonization, infection, and inflammation. Recent efforts have aimed to find therapies that target the biochemical pathway involved in the pathogenesis of this disease. Several case reports indicate the use of different biological agents to achieve long-term remission in patients with recalcitrant Hailey-Hailey disease. Tumor necrosis factor-alpha inhibitors have been used to treat and maintain remission in recalcitrant Hailey-Hailey disease patients, but additional reporting and studies are required. In this case series, we report three cases of recalcitrant Hailey-Hailey disease whose lesions were successfully controlled with adalimumab.

Gonadal Mosaicism as a Rare Inheritance Pattern in Recessive Genodermatoses: Report of Two Cases with Pseudoxanthoma Elasticum and Literature Review.

Germline mosaicism in autosomal recessive disorders is considered a rare disease mechanism with important consequences for diagnosis and patient counseling. In this report, we present two families with PXE in which paternal germline mosaicism for an ABCC6 whole-gene deletion was observed. The first family further illustrates the clinical challenges in PXE, with a typical PXE retinopathy in an apparently heterozygous carrier parent. A systematic review of the literature on gonadal mosaicism in autosomal recessive genodermatoses revealed 16 additional patients. As in most reported families, segregation analysis data are not mentioned, and this may still be an underrepresentation. Though rare, the possibility of germline mosaicism emphasizes the need for variant verification in parents and sibs of a newly diagnosed proband, as it has significant implications for genetic counseling and management.

Cancer and Hidradenitis Suppurativa.

Hidradenitis suppurativa patients have an increased risk of developing cancer. This includes not only hematologic malignancies and solid tumors, but also cutaneous squamous cell carcinoma originating within the hidradenitis suppurativa lesions. The development of squamous cell carcinoma is most commonly associated with Caucasian men who smoke and have severe gluteal or perianal lesions of more than 25 years duration. Other factors that have occasionally been associated with hidradenitis suppurativa-related squamous cell carcinoma include treatment with a tumor necrosis factor-alpha inhibitor (such as infliximab and adalimumab), genodermatoses (such as keratitis-ichthyosis-deafness syndrome and Dowling-Degos disease), and paraneoplastic syndromes (such as hypercalcemia, hypercalcemia-leukocytosis, and paraneoplastic neuropathy). The tumor may demonstrate the presence of human papillomavirus; even after treatment, patients have a poor prognosis since cancer metastasis, or recurrence, or both commonly occurs. The potential role of human papillomavirus vaccination for cancer prevention and early treatment of squamous cell carcinoma with targeted therapy (with an epidermal growth factor inhibitor such as cetuximab) and/or checkpoint inhibitor immunotherapy (such as cemiplimab and pembrolizumab) remains to be determined. Rarely, hidradenitis suppurativa lesions have mimicked cutaneous metastases in patients with visceral malignancy by demonstrating an increased uptake of fluorine-18 fluorodeoxyglucose on positron emission tomography and/or computerized tomography scans. Also, both primary cancers (such as cutaneous squamous cell carcinoma and mucinous adenocarcinoma) and breast cancer skin metastases can masquerade as hidradenitis suppurativa lesions. Therefore, when a lesion is located at a current or prior site of hidradenitis suppurativa that is new or rapidly growing and/or does not respond to hidradenitis suppurativa-directed therapy, prompt evaluation to establish or exclude the diagnosis of cancer should be considered.

Coincidence of acral peeling skin syndrome and Nagashima-type palmoplantar keratosis in a Japanese pedigree with acral skin peeling.

Acral peeling skin syndrome (APSS; MIM 609796) is a rare genodermatosis characterized by painless focal cutaneous exfoliation of the dorsal hands and feet, typically displaying autosomal recessive inheritance. While cases associated with a founder mutation in TGM5 are relatively common in European Caucasian populations, no APSS cases have been reported from Japan or other East Asian countries. In contrast, Nagashima-type palmoplantar keratosis (NPPK; MIM 615598), caused by variants in SERPINB7, is relatively common in East Asia due to founder mutations. We describe a 27-year-old Japanese woman with spontaneous focal cutaneous exfoliation of the dorsal hand following prolonged glove use, indicative of APSS. Histopathological examination revealed a cleft between the stratum corneum and stratum granulosum and within the horny layer of the epidermis, supporting this diagnosis. However, her mother and maternal uncle exhibited similar symptoms, and there was no reported consanguinity in the patient's parents or grandparents, prompting suspicion of an autosomal dominant genodermatosis. Whole-genome sequencing (WGS) revealed compound heterozygous variants in TGM5 (c.1037G>A and c.684 + 1G>A) as suspected causative variants in the patient, leading to an APSS diagnosis, the first reported in East Asia. On the other hand, her mother and maternal uncle were diagnosed with NPPK due to compound heterozygous pathogenic variants in SERPINB7 (c.796C>T and c.455-1G>A). This case highlights the complexity of diagnosing skin disorders when multiple genodermatoses with similar phenotypes exist within a pedigree. Comprehensive genetic analyses, such as whole-exome sequencing and WGS, are invaluable for identifying causative variants in such complex cases.

Heterozygous DSP in-frame deletion in a poodle with syndromic ichthyosis involving additional hair and tooth abnormalities.

Ichthyoses comprise a large heterogeneous group of skin disorders, characterized by generalized scaly and hyperkeratotic skin. We investigated a miniature poodle with early onset generalized scaling, dry and irregularly thickened skin, paw pad hyperkeratosis and abnormalities in hair and teeth. The clinical signs of ichthyosis were confirmed by histopathological examination, which revealed mild epidermal hyperplasia and lamellar orthokeratotic hyperkeratosis. A hereditary condition was suspected and a genetic investigation was initiated. We sequenced the whole genome of the affected dog and searched for potentially causative variants in functional candidate genes for the observed phenotype. The analysis revealed a heterozygous in-frame deletion in DSP, NC_049256.1:g.8804542_8804544del resulting from a de novo mutation event as evidenced by genotyping leukocyte DNA from both parents. The 3 bp deletion is predicted to remove one aspartic acid without disrupting the open reading frame (XM_038584124.1:c.1821_1823del, XP_038440052.1:p.(Asp608del)). The DSP gene encodes desmoplakin, a desmosomal plaque protein, responsible for cell-cell adhesion to provide resistance to mechanical stress in epidermal and cardiac tissues. We hypothesize that the deletion of one amino acid in the N-terminal globular head domain acts in a dominant negative manner and thus impairs the proper connection with other proteins. Several variants in DSP in humans and cattle have been described to result in different phenotypes associated with hair and skin abnormalities, sometimes in combination with variable cardiac and/or dental manifestations. In conclusion, we characterized a new syndromic ichthyosis phenotype in a dog and identified a de novo 3 bp deletion in the DSP gene as causal variant.

Syndromic epidermolysis bullosa simplex subtype due to mutations in the KLHL24 gene: series of case reports in Russian families.

Objective: Epidermolysis bullosa simplex (EBS) is a common, well-characterized type of epidermolysis bullosa. However, some rare syndromic EBS phenotypes are not well described. The accumulation of clinical descriptions of patients with syndromic subtypes of EBS is important for understanding the natural history of the disease and assessing genotype-phenotype correlations. Case summary: We present a series of case reports of the syndromic subtype of EBS associated with mutations in the KLHL24 gene in seven patients from four unrelated families. The clinical features of this rare phenotype in children and adult patients are described in detail. In two families, we revealed pathogenic variant c.1A > G (p.Met1?) in the KLHL24 gene. The third family had c.3G > A (p.Met1?) mutation, and the fourth family had a novel de novo variant c.23del (p.Arg8AsnfsTer2). Conclusion: The description of the clinical manifestations of the disease in two generations of EBS families with different genetic variants allows the assessment and prediction of the natural course and severity of the disease in these families, the risk of complications, and the planning of the amount of medical care necessary.

A case of restrictive dermopathy in a Hutterite newborn: Diagnosis and creative skin-directed management.

Restrictive dermopathy is a lethal autosomal recessive disease characterized by tightly adherent skin, distinctive facial dysmorphisms, arthrogryposis, and pulmonary hypoplasia. While clinical findings are unique, histopathology and genetic analysis are critical for early diagnostic confirmation and to initiate appropriate management for this lethal disease. We report on a preterm Hutterite male neonate with biallelic ZMPSTE24 mutations to highlight the clinical and histopathological features of restrictive dermopathy and share our skin-directed management strategies.

A Long-Term Follow-Up of a Patient with a Novel PORCN Variant and Additional Clinical Features.

Introduction: Focal dermal hypoplasia (FDH) is a genodermatosis also known as Goltz-Gorlin syndrome caused by pathogenic variants in the PORCN gene and inherited in an X-linked dominant manner. Given the course of X-linked dominant inheritance, affected males can only survive in the state of mosaicism for a PORCN pathogenic variant or in the presence of XXY karyotype. FDH is a multisystemic disorder in which cutaneous, ocular, and skeletal systems are primarily affected. Patients also may display intellectual disability and central nervous system abnormalities, yet most may have normal mental development. Case Presentation: We report on a currently 11-year-old female patient with a novel missense heterozygous PORCN variant who exhibited classical ectodermal, skeletal, and ocular findings in addition to mild intellectual disability, left-side diaphragm eventration, and puberty precox, a finding yet unreported in the literature. Conclusion: With this report, we aimed to expand the mutational spectrum and give insight into the importance of neurologic and skeletal system evaluation among other clinical features of FDH. Although gastrointestinal and genitourinary problems can occur during the course of the disease, to our knowledge, left-side diaphragm eventration and puberty precox are new features that have not been reported previously.

Challenges in the Diagnosis and Management of Giant Porokeratosis: A Case Report.

Porokeratosis encompasses a diverse group of dermatoses, both acquired and genetic, marked by a keratinization disorder. Porokeratosis of Mibelli (PKM) presents as solitary plaques or multiple papules/macules with central atrophy and raised hyperkeratotic borders. Here, we present a case of giant porokeratosis (GPK), a rare form often considered a morphological variant of PKM, with unique clinical and histopathological aspects. Our case involves a 29-year-old patient with a 15 × 10 cm irregular plaque on the dorsal aspect of the right hand. The patient was previously prescribed various topical treatments (retinoids, calcineurin inhibitors, and combinations of corticosteroids with vitamin D3 analogs) and systemic retinoids without improvement before presenting to our department. Due to the high risk of neoplastic transformation and the unavailability of imiquimod, the patient was recommended topical 5-fluorouracil treatment. The trajectory of the lesion under treatment revealed a favorable evolution, and the patient was subjected to regular monitoring every three months to assess the ongoing progress. Recognizing GPK as a high-risk variant is crucial for dermatologists, and it requires a personalized approach. Regular monitoring is advised to detect potential malignant transformations promptly. Future research holds promise for diagnostic advancements, refined treatment modalities, and a deeper understanding of the molecular mechanisms underlying malignancy in porokeratosis.

A novel heterozygous frameshift mutation in the KRT6A gene responsible for an uncommon phenotype of pachyonychia congenita: One case report and review of literature.

Pachyonychia congenita is an uncommon autosomal dominant skin disorder characterized by hypertrophic nail dystrophy, palmoplantar keratoderma, oral leukokeratosis, and cutaneous cysts. And fissured tongue is rarely reported in patients with pachyonychia congenita. The disease is primarily associated with mutations in five keratin genes, namely KRT6A, KRT6B, KRT6C, KRT16 or KRT17. Herein we report a 9-year-old Chinese girl who has thickened nails, keratinized plaques, and fissured tongue since birth. To investigate the underlying genetic cause, whole-exome sequencing and Sanger sequencing were performed in this patient and her family members. We identified a candidate variant c.1460-2_1460del (p.S487Lfs*21) in the KRT6A gene (NM_005554.4) by whole-exome sequencing. Sanger sequencing revealed the absence of the mutation in both parents, indicating that it is a de novo variant. Thus, the novel heterozygous frameshift mutation c.1460-2_1460del (p.S487Lfs*21) within exon 9 of KRT6A was identified as the genetic cause of the patient. Our study identified a rare de novo heterozygous frameshift mutation in the KRT6A gene in a patient with pachyonychia congenita presenting fissured tongue. Our findings expand the KRT6A gene mutation spectrum of Pachyonychia congenita, and will contribute to the future genetic counseling and gene therapy for this disease.