Post Zygotic, Somatic, Deletion in KERATIN 1 V1 Domain Generates Structural Alteration of the K1/K10 Dimer, Producing a Monolateral Palmar Epidermolytic Nevus.

Palmoplantar keratodermas (PPKs) are characterized by thickness of stratum corneum and epidermal hyperkeratosis localized in palms and soles. PPKs can be epidermolytic (EPPK) or non epidermolytic (NEPPK). Specific mutations of keratin 16 (K16) and keratin 1 (K1) have been associated to EPPK, and NEPPK. Cases of mosaicism in PPKs due to somatic keratin mutations have also been described in scientific literature. We evaluated a patient presenting hyperkeratosis localized monolaterally in the right palmar area, characterized by linear yellowish hyperkeratotic lesions following the Blaschko lines. No other relatives of the patient showed any dermatological disease. Light and confocal histological analysis confirmed the presence of epidermolityic hyperkeratosis. Genetic analysis performed demonstrates the heterozygous deletion NM_006121.4:r.274_472del for a total of 198 nucleotides, in KRT1 cDNA obtained by a palmar lesional skin biopsy, corresponding to the protein mutation NP_006112.3:p.Gly71_Gly137del. DNA extracted from peripheral blood lymphocytes did not display the presence of the mutation. These results suggest a somatic mutation causing an alteration in K1 N-terminal variable domain (V1). The deleted sequence involves the ISIS subdomain, containing a lysine residue already described as fundamental for epidermal transglutaminases in the crosslinking of IF cytoskeleton. Moreover, a computational analysis of the wild-type and V1-mutated K1/K10 keratin dimers, suggests an unusual interaction between these keratin filaments. The mutation taster in silico analysis also returned a high probability for a deleterious mutation. These data demonstrate once again the importance of the head domain (V1) of K1 in the formation of a functional keratinocyte cytoskeleton. Moreover, this is a further demonstration of the presence of somatic mutations arising in later stages of the embryogenesis, generating a mosaic phenotype.

Spontaneous chromosomal instability in peripheral blood lymphocytes from two molecularly confirmed Italian patients with Hereditary Fibrosis Poikiloderma: insights into cancer predisposition.

Two Italian patients with the initial clinical diagnosis of Rothmund-Thomson syndrome were negative for RECQL4 mutations but showed in peripheral blood cells a spontaneous chromosomal instability significantly higher than controls. Revisiting after time their clinical phenotype, the suggestive matching with the autosomal dominant syndrome Poikiloderma, Hereditary Fibrosing with Tendon Contracture, Myopathy and Pulmonary fibrosis (POIKTMP) was confirmed by identification of the c.1879A>G (p.Arg627Gly) alteration in FAM111B. We compare the overall clinical signs of our patients with those of reported carriers of the same mutation and present the up-to-date mutational repertoire of FAM111B and the related phenotypic spectrum. Our snapshot highlights the age-dependent clinical expressivity of POIKTMP and the need to follow-up patients to monitor the multi-tissue impairment caused by FAM111B alterations. We link our chromosomal instability data to the role of FAM111B in cancer predisposition, pointed out by its implication in DNA-repair pathways and the outcome of pancreatic cancer in 2 out of 17 adult POIKTMP patients. The chromosomal instability herein highlighted well connects POIKTMP to cancer-predisposing syndromes, such as Rothmund-Thomson which represents the first hereditary poikiloderma entering in differential diagnosis with POIKTMP.

Deficiency of PORCN, a regulator of Wnt signaling, is associated with focal dermal hypoplasia.

Focal dermal hypoplasia (FDH) is an X-linked dominant multisystem birth defect affecting tissues of ectodermal and mesodermal origin. Using a stepwise approach of (i) genetic mapping of FDH, (ii) high-resolution comparative genome hybridization to seek deletions in candidate chromosome areas and (iii) point mutation analysis in candidate genes, we identified PORCN, encoding a putative O-acyltransferase and potentially crucial for cellular export of Wnt signaling proteins, as the gene mutated in FDH. The findings implicate FDH as a developmental disorder caused by a deficiency in PORCN.

Eyelid milia en plaque: a treatment challenge with a new CO2 fractional laser.

Milia en plaque (MEP) is an uncommon finding characterized by numerous tiny milia within an erythematous area. Despite its benign and asymptomatic nature, MEP raises cosmetic concerns; moreover, the available treatment modalities for MEP are limited. In view of the few cases described in the literature, no consensus has been reached, with respect to the optimal treatment for MEP, and the choice of therapy should be individualized. We report a case of eyelid milia en plaque successfully treated with a new CO2 fractional laser that is able to ensure superficial ablation of the epidermis remodeling tissue in-depth, with minimal thermal damage and extremely rapid recovery time. The results obtained after only two treatments were good, no scarring or dyschromic changes have been registered. At 1 year, just few recurrent milia were present.

Methotrexate treatment in juvenile localized scleroderma: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: Juvenile localized scleroderma is a chronic progressive fibrotic disorder of the skin that causes permanent disability and aesthetic damage. This study was undertaken to assess the safety and efficacy of methotrexate (MTX) in the treatment of juvenile localized scleroderma. METHODS: In this double-blind study, patients with active juvenile localized scleroderma were randomized (2:1) to receive oral MTX (15 mg/m², maximum 20 mg) or placebo once weekly, for 12 months or until treatment failure. Both groups received oral prednisone (1 mg/kg/day, maximum 50 mg) for the first 3 months. A target lesion was evaluated clinically, with infrared thermography and using a computerized scoring system with skin score rate (SSR) evaluation. Response to treatment was defined as the absence of new lesions, SSR ≤ 1, and a decrease in lesion temperature of at least 10% compared to baseline. Treatment failure was defined as the occurrence of new lesions, SSR > 1, or increased lesion temperature. All analyses were done on the intent-to-treat population. RESULTS: Of the 85 patients screened, 70 (ages 6-17 years) were randomized (46 to the MTX group, 24 to the placebo group). The mean disease duration was 2.3 years. After an initial response in all patients, disease relapsed in 15 MTX-treated patients (32.6%) and 17 placebo-treated patients (70.8%) (P < 0.005). New lesions appeared in 3 MTX-treated patients (6.5%) versus 4 placebo-treated patients (16.7%). The mean SSR decreased from 1 to 0.79 in the MTX group and increased from 1 to 1.1 in the placebo group, and the mean target lesion temperature decreased by 44.4% in the MTX group versus 12.1% in the placebo group. Twenty-six patients in the MTX group (56.5%) and 11 patients in the placebo group (45.8%) developed mild side effects related to treatment. None of the side effects were severe enough to necessitate treatment discontinuation. CONCLUSION: Our findings indicate that MTX is efficacious in the treatment of juvenile localized scleroderma and is well tolerated.

Functional characterization of a novel TP63 mutation in a family with overlapping features of Rapp-Hodgkin/AEC/ADULT syndromes.

Heterozygous mutations in TP63 cause a wide spectrum of autosomal dominant developmental disorders variably affecting skin, limbs, and face. TP63 encodes p63, a protein expressed in two main isoforms (Tap63 and ΔNp63) with critical roles in both cell differentiation and development. Some analyses suggest a relationship of the mutation site to the observed clinical picture, although this link is inconsistent. This suggests an appreciable phenotypic continuity within the TP63-related disorders. We report a 3-month-old boy ascertained for congenital scalp erosion and mild features of ectodermal dysplasia. His mother showed full-blown characteristics of Rapp-Hodgkin syndrome plus intense abdominal and popliteal freckling. Molecular investigation identified the novel TP63 mutation c.1697delG. We used a luciferase reporter assay to compare the effects on the p63 transactivation (TA) activity of c.1697delG with that of the p.Arg280Cys and p.Gln634X mutations, associated with ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome and isolated split hand/foot malformation, respectively. These results demonstrated complex behavior of c.1697delG in the TA of genes involved in epidermal differentiation and development and shed further light in the physiopathology of TP63-related disorders.

Connexin 26 (GJB2) mutations as a cause of the KID syndrome with hearing loss.

KID syndrome (MIM 148210) is an ectodermal dysplasia characterized by the occurrence of localized erythematous scaly skin lesions, keratitis and severe bilateral sensorineural deafness. KID syndrome is inherited as an autosomic dominant disease, due to mutations in the gene encoding gap junction protein GJB2 (connexin 26, Cx26). Cx26 is a component of gap junction channels in the epidermis and in the stria vascularis of the cochlea. These channels play a role in the coordinated exchange of molecules and ions occurring in a wide spectrum of cellular activities. In this paper we describe two patients with Cx26 mutations cause cell death by the alteration of protein trafficking, membrane localization and probably interfering with intracellular ion concentrations. We discuss the pathogenesis of both the hearing and skin phenotypes.

Palmoplantar keratoderma, pseudo-ainhum, and universal atrichia: A new patient and review of the palmoplantar keratoderma-congenital alopecia syndrome.

Palmoplantar keratoderma (PPK) may concur with congenital alopecia (CA) in various genodermatoses. We report on a 10-year-old girl with generalized atrichia and a severe form of PPK causing pseudo-ainhum, sclerodactyly, and contractures, a phenotype not consistent with any well-defined condition. Non-specific additional findings comprised mild nail dystrophy and widespread keratosis pilaris including ulerythema ophryogenes. Direct sequencing of the GJB2 and LOR coding regions yielded normal results. A review identified two additional sporadic and four familial cases with PPK and CA. Comparison between familial cases suggested the existence of two genetically and phenotypically distinct types of PPK-CA: (i) an autosomal dominant form (Stevanovic type), a variable and benign phenotype without significant hand complications, and (ii) a more complex autosomal recessive variant (Wallis type) with contractures, sclerodactyly, and pseudo-ainhum. Nuclear cataract may represent an additional although not constant finding in the Wallis type PPK-CA. Further reports are required to test this preliminary conclusion.

Systematized organoid epidermal nevus with eccrine differentiation, multiple facial and oral congenital scars, gingival synechiae, and blepharophimosis: a novel epidermal nevus syndrome.

Epidermal nevus syndrome is a clinically variable and genetically heterogeneous group of mosaic conditions characterized by the concurrence of extensive epidermal nevus with additional cutaneous and extracutaneous manifestations. This term groups together well-characterized clinical entities, as well as dozens of apparently unique associations, which need further delineation. We report on a 23-year-old woman presenting the previously undescribed combination of widespread eccrine proliferation, multiple facial and oral pox-like lesions, gingival synechiae, blepharophimosis, body asymmetry, and mental retardation. The patient has a healthy monozygotic twin. The eccrine proliferation is intermingled with areas of unaffected skin with a linear/segmental distribution on the limbs. The clinical presentation of such a complex phenotype fits well with the genetic mosaicism theory. The histologic findings, consisting of proliferation of immature to well-formed eccrine duct-like structures located in the deep dermis and interspersed with an abundant fibrous stroma constituted of horizontally oriented collagen fibers, seem a possible hallmark of this condition.

PORCN mutations in focal dermal hypoplasia: coping with lethality.

The X-linked dominant trait focal dermal hypoplasia (FDH, Goltz syndrome) is a developmental defect with focal distribution of affected tissues due to a block of Wnt signal transmission from cells carrying a detrimental PORCN mutation on an active X-chromosome. Molecular characterization of 24 unrelated patients from different ethnic backgrounds revealed 23 different mutations of the PORCN gene in Xp11.23. Three were microdeletions eliminating PORCN and encompassing neighboring genes such as EBP, the gene associated with Conradi-Hünermann-Happle syndrome (CDPX2). 12/24 patients carried nonsense mutations resulting in loss of function. In one case a canonical splice acceptor site was mutated, and 8 missense mutations exchanged highly conserved amino acids. FDH patients overcome the consequences of potentially lethal X-chromosomal mutations by extreme skewing of X-chromosome inactivation in females, enabling transmission of the trait in families, or by postzygotic mosaicism both in male and female individuals. Molecular characterization of the PORCN mutations in cases diagnosed as Goltz syndrome is particularly relevant for genetic counseling of patients and their families since no functional diagnostic test is available and carriers of the mutation might otherwise be overlooked due to considerable phenotypic variability associated with the mosaic status.

Darier disease, multiple bone cysts, and aniridia due to double de novo heterozygous mutations in ATP2A2 and PAX6.

Darier disease (DD) is an autosomal dominant genodermatosis caused by mutations in ATP2A2 and characterized by multiple warty papules coalescing in seborrheic areas and specific histological skin changes. Rare patients are described with variable bone involvement, but this association has never been sufficiently emphasized. Aniridia is a developmental disorder of the eye due to heterozygous mutations in PAX6. DD and aniridia are Mendelian traits mapping on independent loci and have never been reported in association. Here, we describe a 14-year-old girl showing the unique combination of DD, multiple bone cysts, and bilateral aniridia. Molecular investigations demonstrated that such a complex phenotype is due to double de novo heterozygous mutations in ATP2A2 and PAX6. Review of the literature indicates that, in DD, bone cysts are true developmental abnormalities of the skeleton. This finding suggests a role for ATP2A2 in bone biology. More systematic studies are expected in order to estimate the true prevalence of bone cysts in DD and the relationship between skeletal changes and ATP2A2 perturbation.

A rare cause of syndromic hypotrichosis: Nicolaides-Baraitser syndrome.

Nicolaides-Baraitser syndrome (NBS) is a recognizable pattern of human malformations so far reported only in 5 patients. This condition is chiefly characterized by congenital hypotrichosis, peculiar facial gestalt, short metacarpals, interphalangeal swelling, and growth and mental retardation. Although skin manifestations represent a prominent NBS feature, no particular attention has been paid to this condition in the dermatologic literature. Here, we report on the sixth patient with NBS, who requested dermatologic evaluation because of congenital sparse scalp hair. An integrated approach that involved the dermatologist, clinical geneticist, and radiologist was crucial for diagnostic definition. Literature review was carried out to better define the NBS clinical spectrum and to perform an in-depth differential diagnosis with other malformation syndromes presenting with congenital hypotrichosis.

Role of the keratin 1 and keratin 10 tails in the pathogenesis of ichthyosis hystrix of Curth Macklin.

Ichthyosis Hystrix of Curth-Macklin (IH-CM) is a rare manifestation of epidermolytic ichthyosis (EI) that is characterised by generalised spiky or verrucous hyperkeratosis. The disorder is further distinguished by the presence of binucleated cells in the affected skin, whereas epidermolysis and clumping of tonofilaments, as seen in EI, are absent. While IH-CM is associated with mutations in the keratin 1 (KRT1) gene, reports to date have indicated that mutations in the KRT1 gene result in an aberrant and truncated protein tail, essentially affecting the function of the V2 domain. Here, we studied a female sporadic patient who was born with diffused erythrodermic hyperkeratosis and who presented at the age of 13 months with an intense and widespread hyperkeratosis with a papillomatous appearance and typical palmoplantar keratoderma. Genetic analysis demonstrated a "de novo" mutation in the keratin 10 gene (KRT10) consisting of a three-base-pair deletion, resulting in the substitution of amino acids p.Glu445 and p.Ile446 by Asp at the end of the 2B domain of the protein. We performed structural and functional studies showing that this mutation modifies the structure of the paired 2B and V2 K1/10 domains, leading to the disease phenotype. Our results highlight the importance and complexity of the KRT1/10 V2 domain in keratin dimer formation and the potential consequences of its alteration.

Ocular involvement in children with localised scleroderma: a multi-centre study.

BACKGROUND: Most of the available documentation in the literature on ocular involvement in localised scleroderma (LS) are descriptions of single cases in adult patients. This article reports the frequency and specific features of ocular involvement in a large cohort of children with juvenile LS (JLS). METHODS: Data from a large, multi-centre, multinational study of children with LS were used to collect and analyse specific information on ocular involvement. RESULTS: 24 out of 750 patients (3.2%) revealed a significant ocular involvement. 16 were female and 8 male. 16 patients (66.7%) had scleroderma "en coup de sabre" (ECDS) of the face, 5 (20.8%) had the linear subtype, 2 (8.3%) had generalised morphea (GM) and one (4.2%) had plaque morphea (PM). Of the 24 patients with eye involvement, 10 patients (41.7%) reported adnexa (eyelids and eyelashes) abnormalities, 7 (29.2%) anterior segment inflammation (5 anterior uveitis, 2 episcleritis) and 3 central nervous system-related abnormalities. 4 patients presented single findings such as paralytic strabismus (1), pseudopapilloedema (1) and refractive errors (2). Other extracutaneous manifestations were detected in a significantly higher number of patients with ocular involvement and were mostly neurological. CONCLUSION: Ocular abnormalities are not unusual in patients with JLS, especially in the ECDS subtype. They are frequently associated with other internal organ involvement, particularly the central nervous system (CNS). Careful ophthalmic monitoring is recommended for every patient with JLS, but is mandatory in those with skin lesions on the face and/or concomitant CNS involvement.

Dermatitis artefacta in a child.

The high visibility of dermatologic diseases and their easy accessibility make the skin a primary and direct target for dysfunctional behaviors. Self-harm tendencies can frequently be expressed through dermatologic lesions, and dermatitis artefacta falls within this clinical frame. The occurrence of this cutaneous manifestation in children is very rare, with a peak of greater frequency in adolescence. We describe the characteristics of a multidisciplinary intervention-dermatologic and psychologic. Our pediatric patient displays a dermatologic picture that has no etiologic confirmation. The source of this disorder must therefore be found in socio-relational difficulties within the family and school environments, which lead the patient to self-harm behaviors that have a high communication value.

Eruptive disseminated Spitz nevi.

BACKGROUND: The solitary form of Spitz nevus is a common clinical entity in children, typically occurring on the face and extremities. However, less frequent variants of Spitz nevi, such as agminated forms and eruptive disseminated Spitz nevi (EDSN), have been described. The agminated form is characterised by localised clusters or segmental distribution of Spitz nevi on the face, back, or extremities. First described as "eruptive juvenile melanomata", EDSN is the rarest clinical variant, consisting of a widespread eruption of Spitz nevi, most frequently involving the trunk, buttocks, and proximal limbs, and usually occurs in the second to third decade of life. OBJECTIVES: To describe a case of EDSN and review the literature. MATERIALS & METHODS: Twenty-seven cases of EDSN, including a 12-year-old female patient with EDSN presented here, were reviewed. RESULTS: EDSN generally exhibits an abrupt, eruptive onset (developing over few months), followed by a slow progressive course of new lesions that continue to appear over a long period, resulting in hundreds of papules and nodules. In all reported cases, the EDSN lesions involved the trunk, often affecting the legs and arms, and sometimes the scalp. A number of possible precipitating factors were reported. CONCLUSION: A periodic self-examination, total body photography, a dermoscopic 3-6-month follow-up during the eruptive phase (extending to 9-12 months during the stable phase), and prompt surgical excision of lesions that may be malignant is recommended, however, to date, no malignant transformation of EDSN has been reported.

Epidermolysis bullosa simplex with mottled pigmentation due to de novo P25L mutation in keratin 5 in an Italian patient.

Epidermolysis bullosa simplex with mottled pigmentation (EBS-MP) is an autosomal dominant inherited disorder of the skin, which manifests as recurrent blistering, punctate palmo-plantar hyperkeratoses, and mottled pigmentation of the trunk and extremities. Previous reports have identified the P25L mutation within the non-helical V1 domain of keratin 5 as the unique cause of the disease. We found this mutation in the first Italian case of EBS-MP. The proband was heterozygous for the P25L mutation, which occurred de novo as this change was not detected in the peripheral blood DNA of the healthy parents. Our report extends the limited number of EBS-MP cases and gives further evidence that mutation P25L is responsible for this unusual phenotype.