Hiromichi Takama

Identification of programmed cell death in normal human skin tissues by using specific labelling of fragmented DNA

Programmed cell death (PCD) in normal human skin tissues was studied by using in situ specific labelling of fragmented DNA. This labelling method clearly stained the nuclei of Henles layer in the bulb of the anagen hair follicle in serial sections, and the nuclei of the inner root sheath cuticle cells and Huxleys layer cells showed positive staining in the upper part of the hair follicles. This staining pattern was consistent with the sequence of keratinization in the three layers. The nuclei of differentiated cells located at the centre of the sebaceous glands, and those of the granular keratinocyte layer, were also stained. These findings suggest that PCD might play a key role in the terminal differentiation of the epidermis and epidermal appendages.

Pitted keratolysis: clinical manifestations in 53 cases

Pitted keratolysis (PK) has been reported to be more common among bare‐footed people living in tropical regions. It is now known that the disease is not limited to the tropics but has a world‐wide distribution. However, no study has previously been performed analysing the clinical manifestations of the disease in temperate countries. A survey of 53 patients revealed several distinctive clinical features. Hyperhidrosis is the most frequently observed symptom of this condition. Malodour and sliminess of the skin are also distinctive features, evident in 88.7% and 69.8% of the cases, respectively. The most common sites of onset of PK are the pressure‐bearing areas, such as the ventral aspect of the toe, the ball of the foot and the heel. The next most common site is a friction area, the interface of the toes. Lesions are rarely seen on the non‐pressure‐bearing locations. Some of the primary lesions originate as a small defect along the plantar furrow, which gradually grows into the characteristic crateriform pit. Several clinical features are helpful in diagnosing PK.

Whole-exome sequencing identifies ADAM10 mutations as a cause of reticulate acropigmentation of Kitamura, a clinical entity distinct from Dowling-Degos disease

Reticulate acropigmentation of Kitamura (RAK) is a rare genetic disorder of cutaneous pigmentation with an autosomal dominant pattern of inheritance and a high penetration rate. The characteristic skin lesions are reticulate, slightly depressed pigmented macules mainly affecting the dorsa of the hands and feet, which first appear before puberty and subsequently expand to the proximal limb and the trunk. To identify mutations that cause RAK, we performed exome sequencing of four family members in a pedigree with RAK. Fifty-three SNV/Indels were considered as candidate mutations after some condition narrowing. We confirmed the mutation status in each candidate gene of four other members in the same pedigree to find the gene that matched the mutation status and phenotype of each member. A mutation in ADAM10 encoding a zinc metalloprotease, a disintegrin and metalloprotease domain-containing protein 10 (ADAM10), was identified in the RAK family. ADAM10 is known to be involved in the ectodomain shedding of various substrates in the skin. Sanger sequencing of four additional unrelated RAK patients revealed four additional ADAM10 mutations. We identified a total of three truncating mutations, a splice site mutation and a missense mutation in ADAM10. We searched for mutations in the KRT5 gene, a causative gene for the similar pigmentation disorder Dowling-Degos disease (DDD), in all the patients and found no KRT5 mutation. These results reveal that mutations in ADAM10 are a cause of RAK and that RAK is an independent clinical entity distinct from DDD.

Nodular lesion on the sacrococcygeal area in a bicycle rider

Sir, Molluscum contagiosum (MC) is a poxvirus skin infection that often complicates the course of patients with acquired or iatrogenic immunosuppression. Both the clinical and histological features of disease in these cases may be atypical. We report the unique clinical and histological features of a case of fulminant MC infection with concomitant leukaemia cutis in a patient with relapse of chronic myeloid leukaemia (CML) after allogeneic bone marrow transplantation (BMT). A 49-year-old Chinese woman underwent BMT (conditioning: busulphan, cyclophosphamide, total body irradiation) from an HLA identical sister for Ph positive CML in accelerated phase. She engrafted uneventfully with no chronic graft-vs.-host disease (GVHD). Serial bone marrow reassessments, up to 18 months post-BMT, were negative for residual disease by polymerase chain reaction and cytogenetics. At 36 months, she was found to have haematological relapse of CML, with cytogenetic subclonal evolution. She was treated with hydroxyurea and donor lymphocyte infusions (DLI) (6 ́1 10 kg cells infused in three doses) to enhance the graft-vs.-leukaemia (GVL) effect. There was good control of the peripheral cell counts and no evidence of GVHD. A repeat marrow biopsy at 40 months showed suppression of the abnormal clone to 3% of analysed metaphases. Unfortunately, at 46 months the disease progressed again with increased neutrophil counts (52 10 L), and leukaemia cutis documented by skin biopsy (Figs 1a, 1b). This was treated with combination chemotherapy (cytosine arabinoside 150 mg 5, thioguanine 160 mg 5) resulting in normalization of cell count and resolution of all skin lesions. A second course of DLI (4 ́2 10 kg cells) was administered at 49 months post-BMT. Three weeks after DLI, however, the patient presented with a dense eruption of erythematous papular lesions over the entire face, upper limbs and upper trunk. Photography of the lesions was refused. A biopsy of one lesion showed lobules of abnormal epidermal cells with cytoplasm packed with eosinophilic viral inclusion bodies (Fig. 2a). Electron microscopy showed numerous intracytoplasmic poxvirus particles (240 95 nm in size) within the abnormal epidermal cells, consistent with MC (Fig. 2b). In addition, an infiltrate of promyelocytes and immature myeloid blast cells was seen, consistent with recurrent leukaemia cutis. She died 1 week later of an intracranial haemorrhage, probably related to intracerebral disease. The use of DLI is the treatment of choice for relapse of CML after BMT. The main side-effects are profound marrow and immune suppression, with or without acute and chronic GVHD. Reactivation of dormant DNA viruses like cytomegalovirus, varicella zoster and hepatitis B viruses are potential complications of immunosuppression caused by DLI. This is the first report of severe MC complicating DLI. In immunosuppressed hosts, due to the fulminant replication of the poxvirus, the clinical and pathological features of MC can be highly variable, and aggressive treatment is often needed. Viral particles have even been found in the histologically normal skin epidermis adjacent to MC lesions in patients infected with HIV. There have been two previous reports of skin changes in MC mimicking haematological malignancy involving the skin. In our case, the clinical setting and pathological features are highly supportive of a genuine double pathology. It is recognized that post-BMT patients have an increased incidence of leukaemic involvement of extramedullary sites, including the skin. The incidence may be even higher in patients salvaged with DLI, due to a weaker GVL effect outside the marrow. The precise colocalization of MC replication and leukaemic infiltration in the skin lesions may have been due to a high concentration of chemotactic

Deficient stratum corneum intercellular lipid in a Japanese patient with lamellar ichthyosis by a homozygous deletion mutation in SDR9C7

Autosomal recessive congenital ichthyosis (ARCI) is an umbrella term for inherited non-syndromic ichthyosis, which includes harlequin ichthyosis, lamellar ichthyosis (LI), congenital ichthyosiform erythroderma and pleomorphic ichthyosis (also called self-healing/self-improving collodion baby).1 The clinical diversity is matched by genetic heterogeneity, with 11 genes currently implicated in the pathobiology of ARCI,2,3 including the most recent discovery of two missense mutations in SDR9C7 in three consanguineous Lebanese families.4 Here, we describe a case of ARCI (LI phenotype) that has a previously unreported homozygous deletion mutation in SDR9C7. We extend the spectrum of clinical features associated with SDR9C7 mutations, and identify deficient intercellular lipid and malformation of intercellular lipid layers in the stratum corneum. This article is protected by copyright. All rights reserved.

Highly Prevalent LIPH Founder Mutations Causing Autosomal Recessive Woolly Hair/Hypotrichosis in Japan and the Genotype/Phenotype Correlations

Mutations in LIPH cause of autosomal recessive woolly hair/hypotrichosis (ARWH), and the 2 missense mutations c.736T>A (p.Cys246Ser) and c.742C>A (p.His248Asn) are considered prevalent founder mutations for ARWH in the Japanese population. To reveal genotype/phenotype correlations in ARWH cases in Japan and the haplotypes in 14 Japanese patients from 14 unrelated Japanese families. 13 patients had woolly hair, and 1 patient had complete baldness since birth. An LIPH mutation search revealed homozygous c.736T>A mutations in 10 of the patients. Compound heterozygous c.736T>A and c.742C>A mutations were found in 3 of the patients, and homozygous c.742C>A mutation in 1 patient. The phenotype of mild hypotrichosis with woolly hair was restricted to the patients with the homozygous c.736T>A mutation. The severe phenotype of complete baldness was seen in only 1 patient with homozygous c.742C>A. Haplotype analysis revealed that the alleles containing the LIPH c.736T>A mutation had a haplotype identical to that reported previously, although 4 alleles out of 5 chromosomes containing the LIPH c.742C>A mutation had a different haplotype from the previously reported founder allele. These alleles with c.742C>A are thought to be the third founder LIPH mutation causing ARWH. To accurately determine the prevalence of the founder mutations, we investigated allele frequencies of those mutations in 819 Japanese controls. Heterozygous c.736T>A mutations were found in 13 controls (allele frequency: 0.0079; carrier rate: 0.016), and heterozygous c.742C>A mutations were found in 2 controls (allele frequency: 0.0012; carrier rate: 0.0024). In conclusion, this study confirms the more accurate allele frequencies of the pathogenic founder mutations of LIPH and shows that there is a third founder mutation in Japan. In addition, the present findings suggest that the mutation patterns of LIPH might be associated with hypotrichosis severity in ARWH.

Three Cases of Erythema Nodosum Associated with Yersinia Enterocolitica Infection

Three cases of erythema nodosum associated with Yersinia enterocolitica infection were reported. They were diagnosed as Yersinosis following isolation of Yersinia enterocolitica from the feces and from serological investigation.

Herpes zoster of the nipple: rapid DNA-based diagnosis by the loop-mediated isothermal amplification method

A 28-year-old Japanese man presented with grouped erosions and vesicles on an erythematous base affecting the right areola and the surrounding skin. A Tzanck smear from the vesicle revealed giant cells. An initial clinical diagnosis of mammary herpes simplex was considered but to explore the differential diagnosis, viral DNA was amplified by the loop-mediated isothermal amplification (LAMP) method. DNA replication was observed only in varicella zoster virus LAMP mixture, and this confirmed a diagnosis of herpes zoster. The patient was treated with 3000 mg of daily oral valacyclovir for seven days. After antiviral treatment, the lesion had healed and the pain had resolved completely.

Novel and recurrent ATP2A2 mutations in Japanese patients with Darier’s disease

ABSTRACT Darier’s disease (DD, keratosis follicularis: OMIM#124200) is an autosomal dominant skin disorder characterized by multiple dark brown keratotic plaques and warty papules covered by thick crusts. Most cases of DD are caused by mutations in ATP2A2, which is expressed in both the skin and the brain. ATP2A2 encodes the cardiac muscle SERCA2a protein and the ubiquitously expressed SERCA2b. SERCA2 plays an important role as a calcium pump. It is thought that a mutation in ATP2A2 causes dyskeratosis and abnormality of cell-cell adhesion. Here, we report five DD patients from five independent families who presented or were referred to the Nagoya University Hospital in the past five years. We detected five mutations in ATP2A2, including a previously unreported mutation. We observed no apparent genotype/phenotype correlation between types and sites of the ATP2A2 mutations and DD phenotypes in the present series of DD patients. Genetic diagnosis from ATP2A2 mutation search is useful for the definite diagnosis of DD, although it is difficult to predict the severity and prognosis of skin symptoms from the results of the ATP2A2 mutation analysis in DD patients.

Unilateral generalized linear porokeratosis with nail dystrophy

Dear Editor, Porokeratosis is a disorder of abnormal keratinization characterized clinically by well-defined annular lesions with hyperkeratotic ridges. Here, we report a case of unilateral generalized linear porokeratosis with dystrophy of the toenail. A 36-year-old man showed unilateral, brownish-red plaques and round macules on the right side of his trunk and the right extremities, with slight itching (Fig. 1a). The eruptions had been present since childhood. At elementary school age, toenail dystrophy occurred after the appearance of cutaneous hyperkeratotic lesions. The lesions consisted of multiple pigmented hyperkeratotic and verrucous papules and plaques with a sharply demarcated border in a linear distribution. The lesions were distributed along the lines of Blaschko (Fig. 1a). Some of the macules had coalesced, and in some parts of the lesions, annular macules with hyperkeratotic rims were also seen. The linear lesions on the right leg were connected to the lesions in the toes. The nail of the right first toe was dystrophic and showed irregular grooving and pterygium (Fig. 1b,c). No bony abnormality of the affected toe was detected by X-ray examination (Fig. 1d). The patient had no cutaneous lesions on the hands. No nail dystrophy was seen on any finger. There were no mucosal or visceral abnormalities. He had neither immunosuppression nor any systemic disease associated with porokeratosis. He had no family history of porokeratosis. Skin biopsies were taken from affected sites of the abdomen and the leg. Cornoid lamellae were found in the interfollicular epidermis (Fig. 1e). From these clinical and histopathological findings, this case was diagnosed as linear porokeratosis. Two forms of linear porokeratosis exist. In the rare generalized form, the lesions are multiple, and they affect several extremities and involve the trunk. Unilateral generalized linear porokeratosis is extremely rare. Nail involvement in linear parakeratosis is rare. To date, there have been only a few case reports of onychodystrophy in linear porokeratosis. In one case, there was bony narrowing of the digits. Six main variants of porokeratosis have been described. In those variants, nail involvement was reported not only in linear porokeratosis, but also in porokeratosis of Mibelli and porokeratosis plantaris palmaris et disseminata. Though the exact pathogenesis of dystrophic nail is not yet understood, it is possible that nail changes occur through the involvement of the nail matrix and nail bed by atypical hyperproliferative keratinocytes, ultimately resulting in destruction of the whole nail. Cases with nail involvement in linear porokeratosis are not as rare as those in the other porokeratosis variants. We speculate that this is because many cases of linear porokeratosis involve the distal portions of the extremities. Local porokeratosis can be treated by topical therapy, such as with 5-fluorouracil, vitamin D3 analogs, imiquimod or tretinoin creams. For generalized porokeratosis, topical therapies may show variable effectiveness, but they are not practical. Therefore, systemic retinoids were anecdotally used for diffuse porokeratosis. Our patient declined etretinate, the only internal retinoid available in Japan.