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.

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.

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.

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.

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.

Novel physiological RECQL4 alternative transcript disclosed by molecular characterisation of Rothmund-Thomson Syndrome sibs with mild phenotype.

Rothmund-Thomson syndrome is a rare genodermatosis caused by biallelic mutations of the RECQL4 gene and is characterised by poikiloderma, sparse hair, eyelashes and/or eyebrows, small stature, skeletal and dental abnormalities and cancer predisposition. Mutations predicted to result in the loss of RECQL4 protein have been associated with osteosarcoma risk, but mutation(s)-phenotype correlations are better addressed by combined DNA and RNA analyses. We describe two siblings with a mild phenotype, mainly restricted to the skin, who carry the unreported paternal c.2272C>T alteration in exon 14 and the previously reported maternal exon 15 c.2492_2493delAT, both predicted to result in premature termination codons (p.(Arg758*), p.(His831Argfs*52)). However real-time and transcript analysis showed, in the carrier father and affected daughter, increased levels of a novel RECQL4 physiological alternative transcript with partial in-frame skipping of exon 14, generated by increased usage of a weak cryptic splice site. This alternative transcript is expressed in all controls and tested tissues, its upregulation is specific to the paternal c.2272C>T mutation and depends on the abrogation of the binding motifs for SF2 and SRp55 serine/arginine-rich proteins with bypass of the mutation site located in the skipped exon 14 portion. Moreover, in the proband the increased levels of the alternative transcript, likely encoding a protein isoform with residual activity, may compensate for the dearth of the canonical transcript with the c.2492_2493delAT, accounting for the mild clinical phenotype of the siblings. Our results emphasise the value of RNA analysis to better predict the effects of RECQL4 mutations on the clinical phenotype.

Clinical expression and new SPINK5 splicing defects in Netherton syndrome: unmasking a frequent founder synonymous mutation and unconventional intronic mutations.

Netherton syndrome (NS) is a severe skin disease caused by loss-of-function mutations in SPINK5 (serine protease inhibitor Kazal-type 5) encoding the serine protease inhibitor LEKTI (lympho-epithelial Kazal type-related inhibitor). Here, we disclose new SPINK5 defects in 12 patients, who presented a clinical triad suggestive of NS with variations in inter- and intra-familial disease expression. We identified a new and frequent synonymous mutation c.891C>T (p.Cys297Cys) in exon 11 of the 12 NS patients. This mutation disrupts an exonic splicing enhancer sequence and causes out-of-frame skipping of exon 11. Haplotype analysis indicates that this mutation is a founder mutation in Greece. Two other new deep intronic mutations, c.283-12T>A in intron 4 and c.1820+53G>A in intron 19, induced partial intronic sequence retention. A new nonsense c.2557C>T (p.Arg853X) mutation was also identified. All mutations led to a premature termination codon resulting in no detectable LEKTI on skin sections. Two patients with deep intronic mutations showed residual LEKTI fragments in cultured keratinocytes. These fragments retained some functional activity, and could therefore, together with other determinants, contribute to modulate the disease phenotype. This new founder mutation, the most frequent mutation described in European populations so far, and these unusual intronic mutations, widen the clinical and molecular spectrum of NS and offer new diagnostic perspectives for NS patients.

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.

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.

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.

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.

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.

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.