Recessive Mutations in AP1B1 Cause Ichthyosis, Deafness, and Photophobia.

We describe unrelated individuals with ichthyosis, failure to thrive, thrombocytopenia, photophobia, and progressive hearing loss. Each have bi-allelic mutations in AP1B1, the gene encoding the ß subunit of heterotetrameric adaptor protein 1 (AP-1) complexes, which mediate endomembrane polarization, sorting, and transport. In affected keratinocytes the AP-1 ß subunit is lost, and the γ subunit is greatly reduced, demonstrating destabilization of the AP-1 complex. Affected cells and tissue contain an abundance of abnormal vesicles and show hyperproliferation, abnormal epidermal differentiation, and derangement of intercellular junction proteins. Transduction of affected cells with wild-type AP1B1 rescues the vesicular phenotype, conclusively establishing that loss of AP1B1 function causes this disorder.

Segmental basaloid follicular hamartomas derive from a post-zygotic SMO p.L412F pathogenic variant and express hair follicle development-related proteins in a pattern that distinguish them from basal cell carcinomas.

Basaloid follicular hamartomas (BFH) are benign small basaloid skin tumors that can present as solitary or multiple lesions. Congenital BFH lesions arranged in a segmental distribution have been described, suggesting they derive from a somatic post-zygotic mutational event. Previously, BFH were described in Happle-Tinschert syndrome, which results from a post-zygotic SMO variant and is characterized by segmental BFH with variable involvement of the teeth, skeleton, and central nervous system. Here, we describe two patients with isolated segmental BFH and no systemic involvement. Paired whole exome sequencing of BFH and normal tissue revealed a pathogenic SMO c.1234 C>T, p.L412F variant restricted to BFH tissue. We characterized the proliferation index and expression of Hedgehog and Wnt/beta-catenin pathway related proteins in segmental BFH compared to sporadic basal cell carcinomas (BCCs) and found that segmental BFH had a lower proliferation index. Although segmental BFH expressed a similar level of Gli-1 compared to BCCs, levels of LEF-1 and SOX-9 expression in BFH were weaker for both and patchier for LEF-1. Our results show that a somatic SMO activating variant causes segmental BFH. Since these patients are prone to developing BCCs, differences in SOX9, LEF1, and Ki-67 expression can help distinguish between these two basaloid lesions.

Inflammatory linear verrucous epidermal nevus (ILVEN) encompasses a spectrum of inflammatory mosaic disorders.

BACKGROUND: Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare skin disease characterized by pruritic erythematous scaly plaques distributed along the lines of Blaschko. Two cases of ILVEN with CARD14 mutations and one case with a GJA1 mutation have been previously reported. OBJECTIVE: To elucidate the genetic cause of a cohort of patients diagnosed based on clinical and histopathological evaluation with ILVEN. METHODS: We recruited patients diagnosed with ILVEN based on clinical and histopathological criteria. Exome sequencing of affected skin with or without blood/saliva was performed and germline and somatic pathogenic variants were identified. RESULTS: Five patients were enrolled. All had skin lesions from birth or early childhood. Two patients developed psoriasis vulgaris after the diagnosis of ILVEN. The first had a germline heterozygous CARD14 mutation and a post-zygotic hotspot mutation in KRT10. The histopathologic evaluation did not show epidermolytic hyperkeratosis. The second had a post-zygotic hotspot mutation in HRAS. Her ILVEN became itchy once psoriasis developed. One patient was re-diagnosed with linear porokeratosis based on a germline mutation in PMVK and a post-zygotic second-hit mutation. Two patients were re-diagnosed with congenital hemidysplasia with ichthyosiform nevus and limb defect nevus based on germline NSDHL mutations. CONCLUSION: ILVEN is a clinical descriptor for a heterogenous group of mosaic inflammatory disorders. Genetic analysis has the potential to more precisely categorize ILVEN and permits pathogenesis-directed therapies in some cases.

Topical cholesterol/lovastatin for the treatment of porokeratosis: A pathogenesis-directed therapy.

BACKGROUND: Porokeratosis is associated with mevalonate pathway gene mutations. Therapeutic options are few and often limited in efficacy. We hypothesized that topical therapy that aims to replenish cholesterol, an essential mevalonate pathway end-product, and block the accumulation of mevalonate pathway toxic metabolites could alleviate porokeratosis. OBJECTIVE: To study the efficacy of topical cholesterol/lovastatin in different variants of porokeratosis. METHODS: We enrolled a series of 5 porokeratosis patients,1 with disseminated superficial actinic porokeratosis, 2 with porokeratosis palmaris et plantaris disseminata, and 2 with linear porokeratosis. Patients were genotyped before initiation of therapy. Patients then applied topical cholesterol/lovastatin twice daily to a unilaterally defined treatment area for up to 3 months. The response was evaluated and patients photographed at every visit. RESULTS: Three patients had MVD mutations, and 2 patients had PMVK mutations. Treatment with topical cholesterol/lovastatin (but not cholesterol alone) resulted in near complete clearance of disseminated superficial actinic porokeratosis lesions after 4 weeks of therapy and moderate improvement of porokeratosis palmaris et plantaris disseminata lesions and linear porokeratosis lesions. There were no adverse events. LIMITATIONS: Case series design with a small number of patients. CONCLUSION: Topical cholesterol/lovastatin is an effective and well-tolerated therapy for porokeratosis that underscores the utility of a pathogenesis-based therapy that replaces deficient end products and prevents accumulation of potentially toxic precursors.

Post-zygotic ACTB mutations underlie congenital smooth muscle hamartomas.

BACKGROUND: Congenital smooth muscle hamartomas (CSMHs) are benign lesions that share clinical and histopathological features with Becker nevus, a mosaic disorder associated with post-zygotic ACTB mutations. Given the clinical and histopathological overlap between CSMH and Becker nevus, we hypothesized that post-zygotic mutations in ACTB may underlie CSMH. METHODS: Direct sequencing of ACTB gene in affected and unaffected tissue isolated from one case of hemihypertrichosis and hemihypertrophy corresponding to giant segmental CSMH and hemihypertrophy. This was followed by direct sequencing with and without enrichment assay for hotspot ACTB mutations in affected tissue from 12 samples of isolated CSMH from unrelated individuals. RESULTS: In total we identified somatic missense ACTB mutations in 9 out of 13 CSMHs (69%). Mutations were either novel or previously reported in Becker nevi and Becker nevus syndrome. CONCLUSIONS: CSMHs result from post-zygotic ACTB mutations. This study proves that CSMHs and Becker nevi are nosologically related, and expand the phenotypic spectrum of ACTB mutations.

Mutations in KRT10 in epidermolytic acanthoma.

BACKGROUND: Epidermolytic acanthoma (EA) is a rare acquired lesion demonstrating a characteristic histopathological pattern of epidermal degeneration referred to as epidermolytic hyperkeratosis (EHK). On histopathological analysis, EA appears nearly identical to inherited EHK-associated dermatoses such as epidermolytic ichthyosis and ichthyosis bullosa of Siemens. While it has been speculated that EA is caused by mutations in KRT10, KRT1, or KRT2 found in these inherited dermatoses, none have yet been identified. Herein, we aim to identify the contributions of keratin mutations to EA. METHODS: Using genomic DNA extracted from paraffin-embedded samples from departmental archives, we evaluated a discovery cohort using whole-exome sequencing (WES) and assessed remaining samples using Sanger sequencing screening and restriction fragment length polymorphism (RFLP) analysis. RESULTS: DNA from 16/20 cases in our sample was of sufficient quality for polymerase chain reaction amplification. WES of genomic DNA from lesional tissue revealed KRT10 c.466C > T, p.Arg156Cys mutations in 2/3 samples submitted for examination. RFLP analysis of these samples as well as eight additional samples confirmed the mutations identified via WES and identified four additional cases with Arg156 mutations. In sum, 6/11 screened cases showed hotspot mutation in KRT10. CONCLUSIONS: Hotspot mutations in the Arg156 position of KRT10, known to cause epidermolytic ichthyosis, also underlie EA.

Stage-dependent Increase in Expression of miR-155 and Ki-67 and Number of Tumour-associated Inflammatory Cells in Folliculotropic Mycosis Fungoides.

Recent studies suggest that folliculotropic mycosis fungoides (FMF), the most common variant of mycosis fungoides (MF), presents with 2 distinct clinicopathological stages: early indolent stage and more aggressive advanced/tumour stage. To further characterize these stages, miR-155 expression was studied with qRT-PCR and found to be significantly higher in biopsies of tumour-stage FMF compared with early-stage FMF and inflammatory dermatoses. There was no statistically significant difference in miR-155 expression between early-stage FMF and early-stage MF, nor between tumour-stage FMF and tumour-stage MF. Immunohistochemical analysis revealed a significantly increased number of dermal Ki-67+ proliferating lymphocytes in tumour-stage FMF, together with an increased number of CD20+ B cells and CD68+ macrophages compared with early-stage FMF. Thus, similar to classic MF, miR-155, Ki-67 tumour cell immunoreactivity, and certain tumour-infiltrating inflammatory cells are differentially expressed in early- vs tumour-stage FMF. The results of this study corroborate the notion that FMF presents with 2 distinct stages.

Phenotypic expansion of POFUT1 loss of function mutations in a disorder featuring segmental dyspigmentation with eczematous and folliculo-centric lesions.

Appearance of mosaic disorders in thin Blaschko lines suggests that somatic mutations in keratinocyte precursors underlie their pathogenesis. Germline heterozygous mutations in POFUT1 gene cause Dowling-Degos disease (DDD), a skin disease that features flexural reticulated hyperpigmentation and follicular-based lesions. POFUT1 mosaicism has not been described to date. Here, we describe a 9-year-old female with segmental hyper- and hypopigmented patches with overlying eczematous plaques and follicular papules. Employing paired whole exome sequencing of saliva and keratinocytes isolated from affected skin, we found a novel germline heterozygous POFUT1 deletion causing frameshift and premature codon termination and somatic copy-neutral loss of heterozygosity on chromosome 20 encompassing POFUT1. Expression levels of POFUT1 as well as other key regulators of the notch signaling pathway-NOTCH1, NOTCH2, and HES1-were reduced in affected keratinocytes compared with normal keratinocytes. Our findings provide the first evidence of POFUT1 postzygotic mutation and a phenotypic expansion of POFUT1 loss of function mutations. We show that a recessive loss of function mutation in POFUT1 produces a distinct clinical presentation with features (e.g., dermatitis) that are absent in the generalized form of DDD. This study demonstrates how analysis of mosaic disorders can reveal unexpected phenotypes for known genes.

Review of genodermatoses with characteristic histopathology and potential diagnostic delay.

Advances in human genetics have enabled discovery of new genes for inherited skin diseases and cutaneous malformations as well as refined categorization of genodermatoses. Careful phenotyping has been central to genetic discoveries, and it provides critical clues for clinical diagnoses, particularly when the skin disorder is not congenital. This article will review several lesser-known genodermatoses that often present after infancy with recognizable histopathologic features.

Risk for hepatitis B and C virus reactivation in patients with psoriasis on biologic therapies: A retrospective cohort study and systematic review of the literature.

BACKGROUND: Patients with psoriasis on biologic therapies and a history of viral hepatitis carry a risk for reactivation. OBJECTIVE: We evaluated safety of biologic therapies in psoriasis patients seropositive for hepatitis B or C viruses (HBV, HCV). METHODS: A retrospective cohort study design was used. Clinical and laboratory data for 30 patients undergoing biologic therapy who were seropositive for HBV or HCV were evaluated. Next, a systematic review was performed. Primary outcomes were hepatitis and viral reactivation during therapy. Treatment duration and antiviral prophylaxis were also recorded. RESULTS: Serology indicated HCV infection in 4 patients, past HBV infection in 17 patients, isolated core antibody in 8 patients, and chronic HBV infection in 1 patient. During follow-up (mean 4.85 ± 3.1 years), no patients experienced hepatitis or viral reactivation. The systematic review of the literature included 49 studies comprising 312 patients followed for a mean of 30.9 months. Viral reactivation occurred in 2/175 patients who were seropositive for core antibody and 3/97 with HCV infection (yearly rates, 0.32% and 2.42%, respectively) compared with 8/40 patients with chronic HBV infection (yearly rate, 13.92%). Three of these 8 patients with reactivated HBV infection received antiviral prophylaxis. LIMITATIONS: We pooled heterogeneous studies evaluating different biologic therapies. CONCLUSION: Biologic therapies pose minimal risk for viral reactivation in low-risk patients without hepatitis seropositive for HCV or HBV core antibody but are a considerable risk in patients with chronic HBV infection, highlighting the necessity of antiviral prophylaxis.

Venous thromboembolism in patients with pemphigus: A cohort study.

BACKGROUND: Venous thromboembolism (VTE) has been reported to be a significant cause of death in patients with pemphigus. OBJECTIVE: We sought to assess the incidence and characteristics of VTE in patients with pemphigus. METHODS: A retrospective study following a cohort of 172 patients with newly diagnosed pemphigus for the development of VTE was conducted. RESULTS: Over a mean follow-up time of 4 years, 10 patients (6%) had development of VTE at a median of 4 months from pemphigus diagnosis. The highest risk was found in the first year, at 5 VTE events per 100 patient-years or a 5% VTE risk for that first year. Five patients had deep vein thromboses, 4 had pulmonary embolisms, and 1 had both. Age and gender were not related to the VTE risk. Most patients had VTE risk factors, either hereditary or acquired as the result of pemphigus treatments and their complications, including hospitalization, immobilization, and infections. LIMITATIONS: The use of existing health records limited the assessment of asymptomatic VTE and VTE risk factors; a matched control population was not studied. CONCLUSIONS: VTEs are not rare in patients with pemphigus, more so in the first year after diagnosis. VTE risk must be assessed in all patients, especially when hospitalized, and thrombo-prophylaxis should be initiated in qualifying cases.

Association of bullous pemphigoid with malignancy: A systematic review and meta-analysis.

BACKGROUND: Studies evaluating whether malignancy rate is increased in patients with bullous pemphigoid (BP) have reached conflicting results. OBJECTIVE: We sought to determine whether BP is associated with malignancy. METHOD: Medline, EMBASE, the Cochrane library, and reference lists of included studies were searched for comparative studies that evaluated the relationship between BP and malignancy. Data were analyzed on the basis of study design: cross-sectional, case control, and cohort. A meta-analysis was performed by using a random effects model to estimate pooled odds ratio. RESULTS: The review included 8 studies. No association between BP and overall cancer was found for any of the study designs. Although a single cohort study reported an association with lymphoid leukemia and kidney and larynx cancer, a pooled analysis of case-control studies did not. A pooled analysis of cross-sectional studies found a significant association between BP and hematologic malignancies. LIMITATIONS: The paucity of well-designed studies hindered the possibility of proving or disproving the BP-cancer association. CONCLUSION: We did not find an association of BP with overall malignancy, but a possible association with hematologic malignancy was observed.

New insights into folliculotropic mycosis fungoides (FMF): A single-center experience.

BACKGROUND: It is generally accepted that folliculotropic mycosis fungoides (FMF) is usually typified by indurated plaques and tumors mainly on the head/neck and an aggressive course. However, its clinical manifestations have long been recognized to be quite variable, and some studies indicate a better prognosis for certain presentations. OBJECTIVE: We sought to summarize our experience with the clinicopathological presentations of FMF and impact on prognosis. METHODS: Data were collected retrospectively for adults with FMF followed up prospectively at a tertiary medical center in 1995 through 2014. RESULTS: In all, 34 patients presented with follicle-based patch/flat plaques, keratosis pilaris-like lesions, and/or acneiform lesions, defined clinically as early stage (IA, IB), and 15 presented with follicle-based infiltrated plaques and/or tumors, defined as advanced stage (IIB). The head/neck was involved in all tumor-stage cases, whereas early-stage lesions involved mainly the trunk/limbs. The tumor stage was characterized by more pruritus, heavier perifollicular infiltrates, greater vertical depth, and more frequent presence of eosinophils. On multivariate analysis, infiltrate density was the only significant histopathological discriminator between the stages. Estimated 5-year survival was 0.94 in the early-stage group and 0.69 in the tumor-stage group. LIMITATIONS: Lack of long-term follow-up and relatively small sample are limitations. CONCLUSION: FMF presents with 2 distinct patterns of clinicopathologic features, early stage and advanced stage, each with different prognostic implications.

Intra-familial Variation in Clinical Phenotype of CARD14-related Psoriasis.

Psoriasis is a multifactorial chronic inflammatory disease. Monogenic psoriasis has been described recently, including dominantly inherited plaque and generalized pustular types, related to activating mutations in the CARD14 gene. We describe here a family with CARD14-related psoriasis, exhibiting an extreme variability of clinical presentation (from mild plaque-type to generalized pustular psoriasis) and early disease onset. The affected family members harboured the c.349G>A [p.Gly117Ser] mutation in CARD14, which has not previously been linked to pustular psoriatic phenotype. Furthermore, most severely affected individuals carried 3 additional CARD14 coding region polymorphisms (rs2066964, rs34367357 and rs11652075), suggesting their possible effect on disease expression. Early-onset psoriasis co-segregated with the HLA-C*0602, indicating that HLA-C*0602 could potentially modulate the time of disease onset. In summary, this paper describes a family with CARD14-related psoriasis and discusses the possible influence of the specific haplotypes on intra-familial variation in the clinical phenotype of the disease.

Picosecond lasers for tattoo removal: a systematic review.

Given that the pigment particles in tattoos have a relaxation time of <10 ns, picosecond lasers would be expected to be more effective than nanosecond lasers in tattoo removal. To systematically review the evidence regarding the effectiveness and safety of picosecond lasers for tattoo removal, Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and reference lists were searched for relevant trials. The primary outcome was >70 % clearance of tattoo pigment. Secondary outcomes were 90-100 % clearance of tattoo pigment, number of laser sessions required, and adverse effects. Eight trials were included, six with human participants (160 participants) and 2 with animal models. Seven of the eight trials explored the usage of either 755, 758, 795, 1064, or 1064/532-nm picosecond lasers for black and blue ink tattoos. In the human trials, 69-100 % of tattoos showed over 70 % clearance of pigment after 1-10 laser treatments. Reported side effects included pain, hyperpigmentation and hypopigmentation, blister formation and transient erythema, edema, and pinpoint bleeding. Included articles varied in type of laser investigated, mostly non-comparative studies and with a medium to high risk of bias. There is sparse evidence that picosecond lasers are more effective than their nanosecond counterparts for mainly black and blue ink tattoo removal, with minor side effects.

The role of adjuvant therapy in pemphigus: A systematic review and meta-analysis.

BACKGROUND: The assumption that adjuvant modalities have added value to oral glucocorticoids in the treatment of pemphigus is intuitively sound but has not been conclusively proven. OBJECTIVE: We sought to compare the efficacy and safety of oral glucocorticoid treatment with or without adjuvants for pemphigus vulgaris and pemphigus foliaceus. METHODS: We performed a systematic review and meta-analysis of randomized controlled trials. The primary outcome was remission. Secondary outcomes were disease control, time to disease control, relapse, time to relapse, cumulative glucocorticoid dose, withdrawal because of adverse events, and all-cause death. Trials were pooled irrespective of adjuvant type evaluated. RESULTS: Ten trials (559 participants) were included. Adjuvants evaluated were azathioprine, mycophenolate mofetil, cyclophosphamide, cyclosporine, intravenous immunoglobulin, plasma exchange, and infliximab; not all were included in every analysis. Although adjuvants were not beneficial for achieving remission, they were found to collectively decrease the risk of relapse by 29% (relative risk 0.71, 95% confidence interval 0.53-0.95). LIMITATIONS: Different adjuvants were pooled together. CONCLUSION: Adjuvants have a role in pemphigus treatment, at least in reducing the risk of relapse. Further randomized controlled trials of other promising modalities are warranted.

Persistent Cutaneous Lesions of Darier Disease and Second-Hit Somatic Variants in ATP2A2 Gene.

Importance: Darier disease (DD) is a rare genetic skin disorder caused by heterozygous variants in the ATP2A2 gene. Clinical manifestations include recurrent hyperkeratotic papules and plaques that occur mainly in seborrheic areas. Although some of the lesions wax and wane in response to environmental factors, others are severe and respond poorly to therapy. Objective: To investigate the molecular mechanism underlying the persistency of skin lesions in DD. Design, Setting, and Participants: In this case series, DNA was extracted from unaffected skin, transient and persistent lesional skin, and blood from 9 patients with DD. Genetic analysis was used using paired-whole exome sequencing of affected skin and blood or by deep sequencing of ATP2A2 of affected skin. Chromosomal microarray analysis was used to reveal copy number variants and loss of heterozygosity. All variants were validated by Sanger sequencing or restriction fragment length polymorphism. Interventions or Exposures: Paired whole-exome sequencing and deep sequencing of ATP2A2 gene from blood and skin samples isolated from persistent, transient lesions and unaffected skin in patients with DD. Main Outcomes and Measures: Germline and somatic genomic characteristics of persistent and transient cutaneous lesions in DD. Results: Of 9 patients with DD, all had heterozygous pathogenic germline variants in the ATP2A2 gene, 6 were female. Participant age ranged from 40 to 69 years on enrollment. All 11 persistent skin lesions were associated with second-hit somatic variants in the ATP2A2 gene. The somatic variants were classified as highly deleterious via combined annotation-dependent depletion (CADD) scores or affect splicing, and 3 of them had been previously described in patients with DD and acrokeratosis verruciformis of Hopf. Second-hit variants in the ATP2A2 gene were not identified in the transient lesions (n = 2) or the normal skin (n = 2). Conclusions and Relevance: In this study, persistent DD lesions were associated with the presence of second-hit somatic variants in the ATP2A2 gene. Identification of these second-hit variants offers valuable insight into the underlying mechanisms that contribute to the lasting nature of persistent DD lesions.