Peter Itin

Mutations in the human connexin gene GJB3 cause erythrokeratodermia variabilis

Erythrokeratodermia variabilis (EKV, OMIM 133200) is an autosomal dominant genodermatosis with considerable intra- and interfamilial variability. It has a disfiguring phenotype characterized by the independent occurrence of two morphologic features: transient figurate red patches and localized or generalized hyperkeratosis (Fig. 1). Both features can be triggered by external factors such as trauma to the skin. After initial linkage to the RH locus on 1p (Refs 2,3), EKV was mapped to an interval of 2.6 cM on 1p34-p35, and a candidate gene (GJA4) encoding the gap junction protein α-4 (connexin 31, Cx31) was excluded by sequence analysis. Evidence in mouse suggesting that the EKV region harbours a cluster of epidermally expressed connexin genes led us to characterize the human homologues of GJB3 (encoding Cx31) and GJB5 (encoding Cx31.1). GJB3, GJB5 and GJA4 were localized to a 1.1-Mb YAC in the candidate interval. We detected heterozygous missense mutations in GJB3 in four EKV families leading to substitution of a conserved glycine by charged residues (G12R and G12D), or change of a cysteine (C86S). These mutations are predicted to interfere with normal Cx31 structure and function, possibly due to a dominant inhibitory effect. Our results implicate Cx31 in the pathogenesis of EKV, and provide evidence that intercellular communication mediated by Cx31 is crucial for epidermal differentiation and response to external factors.

Incidence of bullous pemphigoid and pemphigus in Switzerland: a 2-year prospective study.

Background  Bullous pemphigoid (BP), pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are autoimmune bullous diseases characterized by the presence of tissue‐bound and circulating autoantibodies directed against disease‐specific target antigens of the skin. Although rare, these diseases run a chronic course and are associated with significant morbidity and mortality. There are few prospective data on gender‐ and age‐specific incidence of these disorders.

Diagnosis and Treatment of Lichen Sclerosus

Lichen sclerosus (LS) is a chronic, inflammatory, mucocutaneous disorder of genital and extragenital skin. LS is a debilitating disease, causing itch, pain, dysuria and restriction of micturition, dyspareunia, and significant sexual dysfunction in women and men. Many findings obtained in recent years point more and more towards an autoimmune-induced disease in genetically predisposed patients and further away from an important impact of hormonal factors. Preceding infections may play a provocative part. The role for Borrelia is still controversial. Trauma and an occlusive moist environment may act as precipitating factors. Potent and ultrapotent topical corticosteroids still head the therapeutic armamentarium. Topical calcineurin inhibitors are discussed as alternatives in the treatment of LS in patients who have failed therapy with ultrapotent corticosteroids, or who have a contraindication for the use of corticosteroids. Topical and systemic retinoids may be useful in selected cases. Phototherapy for extragenital LS and photodynamic therapy for genital LS may be therapeutic options in rare cases refractory to the already mentioned treatment. Surgery is restricted to scarring processes leading to functional impairment. In men, circumcision is effective in the majority of cases, but recurrences are well described. Anogenital LS is associated with an increased risk for squamous cell carcinoma of the vulva or penis. This review updates the epidemiology, clinical presentation, histopathology, pathogenesis, and management of LS of the female and male genitals and extragenital LS in adults and children.

Regression of basal cell carcinoma by intralesional interferon-alpha treatment is mediated by CD95 (Apo-1/Fas)-CD95 ligand-induced suicide.

Basal cell carcinoma (BCC) is the most common skin cancer in humans, and although metastasis rarely occurs, the tumor cells are nevertheless able to invade and destroy the surrounding tissue. Intralesional injection of IFN-alpha has been found to be highly effective in inducing BCC regression by an unknown mechanism. We show that in untreated patients, BCC cells express CD95 ligand, but not the receptor, which may allow tumor expansion by averting the attack of activated CD95 receptor-positive lymphoid effector cells. The CD95 ligand of BCC cells is functional as CD95-positive cells incubated on BCC cryosections become apoptotic and are lysed. In IFN-alpha-treated patients BCC cells express not only CD95 ligand but also CD95 receptor, whereas the peritumoral infiltrate that mainly consists of CD4+ T cells predominantly contains CD95 receptor and only few CD95 ligand-positive cells. Thus, in treated patients BCC most likely regresses by committing suicide through apoptosis induction via CD95 receptor-CD95 ligand interaction.

Eosinophilic fasciitis 30 years after - what do we really know? Report of 11 patients and review of the literature.

Background: Eosinophilic fasciitis (EF) is a rare fibrosing disorder associated with peripheral eosinophilia and scleroderma-like induration of the distal extremities which affects substantially quality of life. Although the disease has been described 30 years ago, the etiology and pathomechanisms are still obscure, and consensus for therapy is lacking. Numerous case reports of patients with EF exist but series are scarce. Patients and Methods: Eleven patients with EF from the Department of Dermatology, Kantonsspital Aarau, the University Hospital Basel and the Outpatient Clinic of Dermatology, Triemli Hospital Zurich, Switzerland, were retrospectively studied. Results: In 4 patients the initial diagnosis was not recognized by the referring nondermatologists. The median age was 55 years, excluding the youngest patient ever diagnosed with EF (age = 1 year). All patients showed an induration of the skin, which led to painful contractures in the joints in 3 cases. All but 2 patients demonstrated edema. A slight predominance of the upper extremities was observed. Sclerodactyly was noticed in 1 patient. Three patients reported an initial trauma at the affected site. Two patients were tested positive for borreliosis. One patient subsequently developed aplastic anemia and Hashimoto thyroiditis. Visceral or extracutaneous involvement was absent. Eight patients had a full or partial recovery under corticosteroids whereas in 2, improvement could be achieved only with cyclosporine, azathioprine or cyclophosphamide. Conclusions: The diagnosis of EF can be established by clinical, laboratory and histological findings. In general, corticosteroids are highly efficacious in EF and only a minority of patients need other immunosuppressive or cytostatic drugs.

Disorders of Pigmentation

Skin color is highly individual and the variations are controlled by numerous genes. The different skin colors result from the size and number of melanosomes and do not mirror the amount of melanocytes. Disorders of pigmentation can result from migration abnormalities of melanocytes from the neural crest to the skin during embryogenesis. In addition, impairment of melanosome transfer to the surrounding keratinocytes, an alteration in melanin synthesis and a defective degradation or removal of melanin may lead to abnormal skin pigmentation. Immunologic or toxic mediated destructions of melanocytes can end in pigmentation disorders. Disorders of pigmentation are classified in hypo‐ or hyperpigmentation which can occur as a genetic or acquired disease. They can manifest locally or diffuse. Congenital hypopigmentation can be restricted to the skin as in piebaldism or they represent a systemic disease as in Menkes disease or phenylketonuria. Localized hypo‐ or hyperpigmentation in children may serve as markers for systemic diseases. Ash‐leaf hypopigmentation are characteristic for tuberous sclerosis and more than 5 café‐au‐lait spots suggest neurofibromatosis 1 (von Recklinghausen disease). The most common autoimmune‐induced depigmentation is vitiligo. Generalized hyperpigmentation only rarely reflects a primary genetic disorder but is most often from acquired diseases as in Addison disease, secondary hemochromatosis or primary biliary cirrhosis. Treatment of pigmentation disorders are based on a diagnosis which sometimes allow a specific intervention. Cosmetically acceptable results are difficult to obtain.

Naegeli-Franceschetti-Jadassohn syndrome and dermatopathia pigmentosa reticularis: two allelic ectodermal dysplasias caused by dominant mutations in KRT14.

Naegeli-Franceschetti-Jadassohn syndrome (NFJS) and dermatopathia pigmentosa reticularis (DPR) are two closely related autosomal dominant ectodermal dysplasia syndromes that clinically share complete absence of dermatoglyphics (fingerprint lines), a reticulate pattern of skin hyperpigmentation, thickening of the palms and soles (palmoplantar keratoderma), abnormal sweating, and other subtle developmental anomalies of the teeth, hair, and skin. To decipher the molecular basis of these disorders, we studied one family with DPR and four families with NFJS. We initially reassessed linkage of NFJS/DPR to a previously established locus on 17q11.2-q21. Combined multipoint analysis generated a maximal LOD score of 8.3 at marker D17S800 at a recombination fraction of 0. The disease interval was found to harbor 230 genes, including a large cluster of keratin genes. Heterozygous nonsense or frameshift mutations in KRT14 were found to segregate with the disease trait in all five families. In contrast with KRT14 mutations affecting the central alpha -helical rod domain of keratin 14, which are known to cause epidermolysis bullosa simplex, NFJS/DPR-associated mutations were found in a region of the gene encoding the nonhelical head (E1/V1) domain and are predicted to result in very early termination of translation. These data suggest that KRT14 plays an important role during ontogenesis of dermatoglyphics and sweat glands. Among other functions, the N-terminal part of keratin molecules has been shown to confer protection against proapoptotic signals. Ultrastructural examination of patient skin biopsy specimens provided evidence for increased apoptotic activity in the basal cell layer where KRT14 is expressed, suggesting that apoptosis is an important mechanism in the pathogenesis of NFJS/DPR.

Cutaneous Graft-versus-Host Disease: A Guide for the Dermatologist

Graft-versus-host disease (GVHD) is defined by the aggregation of clinical and pathological manifestations in a recipient of allogeneic stem cells or bone marrow transplantation in which specific immunological as well as nonspecific phenomena lead to characteristic features. GVHD is one of the major complications after hematopoietic stem cell transplantations and responsible for posttherapeutic morbidity, mortality and decrease in quality of life of those patients. GVHD is critically induced and maintained by donor immunocompetent cells that particularly attack epithelia of fast proliferating tissues such as those from the liver, gastrointestinal tract and skin. On the basis of the time of presentation, cutaneous GVHD has been originally divided into an acute and chronic disease. The latter has traditionally been further subclassified into a more epithelial or lichenoid and a predominantly dermal or sclerodermoid form. With respect to the growing importance of this therapeutic procedure and increasing numbers of outpatients presenting with chronic GVHD, this article summarizes the updated knowledge on this disease focused for the dermatologist, and additionally it emphasizes the recent consensus documents on the various aspects of chronic GVHD of the National Institute of Health.

Oral hairy leukoplakia in a HIV-negative renal transplant patient: a marker for immunosuppression?

We report the case of a 58-year-old renal transplant patient who developed oral hairy leukoplakia. Examination for HIV-1 and HIV-2 infection was negative. Biopsy of the lateral tongue showed ballooned prickle cells and electron microscopy revealed herpes-type viruses. In situ hybridization and examinations with the Southern blot technique yielded Epstein-Barr virus. Serology for Epstein-Barr virus was reactive. Immunological investigation of the patient showed a marked decrease of T-helper and T-suppressor cells as the result of immunosuppressive regimen. Oral hairy leukoplakia may be a marker for severe immunosuppression but is not necessarily associated with HIV infection.

Kindler syndrome: extension of FERMT1 mutational spectrum and natural history.

Mutations in the FERMT1 gene (also known as KIND1), encoding the focal adhesion protein kindlin‐1, underlie the Kindler syndrome (KS), an autosomal recessive skin disorder with an intriguing progressive phenotype comprising skin blistering, photosensitivity, progressive poikiloderma with extensive skin atrophy, and propensity to skin cancer. Herein we review the clinical and genetic data of 62 patients, and delineate the natural history of the disorder, for example, age at onset of symptoms, or risk of malignancy. Although most mutations are predicted to lead to premature termination of translation, and to loss of kindlin‐1 function, significant clinical variability is observed among patients. There is an association of FERMT1 missense and in‐frame deletion mutations with milder disease phenotypes, and later onset of complications. Nevertheless, the clinical variability is not fully explained by genotype–phenotype correlations. Environmental factors and yet unidentified modifiers may play a role. Better understanding of the molecular pathogenesis of KS should enable the development of prevention strategies for disease complications. Hum Mutat 32:1204–1212, 2011. ©2011 Wiley Periodicals, Inc.