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Adult mastocytosis is an incurable clonal disease associated with c-KIT mutations, mostly in exon 17 (D816V). In contrast, pediatric mastocytosis often spontaneously regresses and is considered a reactive disease. Previous studies on childhood mastocytosis assessed only a few patients and focused primarily on codon 816 mutations, with various results. In this study, we analyzed the entire c-KIT sequence from cutaneous biopsies of 50 children with mastocytosis (ages 0-16 years). A mutation of codon 816 (exon 17) was found in 42% of cases, and mutations outside exon 17 were observed in 44%. Unexpectedly, half of the mutations were located in the fifth Ig loop of c-KIT's extracellular domain, which is encoded by exons 8 and 9. All mutations identified in this study were somatic and caused a constitutive activation of c-KIT. There was no clear phenotype-genotype correlation, no clear relationship between the mutations and familial versus spontaneous disease, and no significant change in the relative expression of the c-KIT GNNK+ and GNNK isoforms. These findings strongly support the idea that, although pediatric mastocytosis can spontaneously regress, it is a clonal disease most commonly associated with activating mutations in c-KIT.

Rothmund-Thomson syndrome (RTS), a rare recessive autosomal disorder, presents genome instability and clinical heterogeneity with growth deficiency, skin and bone defects, premature aging symptoms and cancer susceptibility. A subset of RTS patients presents mutations of the RECQL4 gene, member of the RecQ family of DNA helicases, including the RECQL2 (BLM) and RECQL3 (WRN) genes, defective in the cancer prone Bloom and Werner syndromes, respectively. Analysis of the RECQL4 gene in six clinically diagnosed RTS patients shows five patients, including two siblings, with eight mutations mainly located in the helicase domain, three patients presenting two mutations. The alterations include four missense mutations, one nonsense mutation and the same frameshift deletion, g.2881delG in exon 9 found in three patients. Seven RECQL4 polymorphisms, two being new, have also been identified. Primary RTS fibroblasts from these RTS patients show no sensitivity to a wide variety of genotoxic agents including ionizing or ultraviolet irradiation, nitrogen mustard, 4NQO, 8-MOP, Cis-Pt, MMC, H2O2, HU, or UV plus caffeine which could be related to the RECQL4 alterations identified here. This is in contrast with the DNA damage sensitive Bloom and Werner cells and highlights the complexity of the numerous RecQ protein functions implicated in the different cellular pathways required for maintaining genomic integrity.

The analysis of phenotype-genotype correlations of patients suffering from recessive dystrophic epidermolysis bullosa (RDEB) evidenced intrafamilial and interfamilial phenotype variability occurring for the same mutation of COL7A1; this underscores the role of other genetics environmental factors in the expressivity of the disease. In this work, we checked whether matrilysin 1 (matrix metalloproteinase (MMP)7) could take part in the epidermal detachment in RDEB. Furthermore, we investigated epigallocatechin 3 gallate (EGCG) to determine whether it could inhibit matrilysin activities on collagen type VII and fibrillin 1 known to be associated with the dermo-epidermal junction. In this work, matrilysin 1 was detected in affected and unaffected skins of the three RDEB patients; furthermore, MMP7 was shown to degrade ex vivo on healthy normal skin collagen VII and fibrillin 1. Thus, we suspect that MMP7 could take an active part in the epidermal detachment occurring during RDEB. We evidenced that EGCG in in vitro as well as in ex vivo experiments was a good inhibitor of MMP7 and developed a good protection of collagen type VII and fibrillin 1 susceptible of being degraded by MMP7. We therefore propose that EGCG could be used beneficially in patients suffering from RDEB.

We report three unrelated patients affected at birth with an unusually severe form of epidermolysis bullosa simplex Dowling-Meara type (EBS-DM) because of mutations in KRT14 encoding keratin 14. Two patients were heterozygous for the previously described p.M119T mutation. The third patient was heterozygous for a novel c.1246delC mutation predicting the replacement of the helix termination peptide and the tail domain by a 25 amino-acid aberrant carboxyterminal sequence. At age 2 years, patients carrying the p.M119T mutation still suffered from severe EBS-DM, whereas the patient harboring the c.1246delC mutation has improved over time. These cases illustrate genotype-phenotype correlations and have implications for genetic counselling of EBS.

During pregnancy, maternal cells may enter the fetal circulation and persist until adulthood. The fate of these cells remains unknown. As unexplained T-cell-mediated conditions such as pityriasis lichenoides (PL) may occur in children, we aimed at identifying maternal cells in lesional skin of PL and controls. Archived skin biopsy specimens from young males with PL, atopic dermatitis, or normal skin were scanned for the presence of female (presumably maternal) cells using fluorescence in situ hybridization (FISH) with X and Y chromosome-specific probes. Phenotyping of maternal cells relied on FISH combined with anti-CD45, anti-CD1a, or anti-cytokeratin labelling, identifying leukocytes, Langerhans cells, and keratinocytes, respectively. Maternal cells were found in PL (11/12) and controls (4/7), but their average frequency was higher in PL: 99 per million cells as compared to 5 per million cells in controls (P = 0.005). In the epidermis, the maternal microchimeric cells were labelled by anti-cytokeratin in all cases. We identified maternally derived keratinocytes in the skin of male children with inflammatory skin disorders. These cells may either help repair the damaged skin or home initially in the skin and trigger a host (child) versus graft (mother) disease.

A number of COL7A1 mutations have now been reported in recessive dystrophic epidermolysis bullosa patients, and the analysis of phenotype-genotype correlations showed evidence for interfamilial and intrafamilial phenotypic variability, occurring for the same mutation. Collagenase and stromelysin activities have been found to be overexpressed in skin cultures of some recessive dystrophic epidermolysis bullosa patients, and tissue destruction in the disease process might result from an imbalance of metalloproteinases (MMP) over tissueinhibitor of metalloproteinases (TIMP). So we suspected that the phenotypic variability for the same mutation could be linked to other genetic or environmental factors, as a particular balance between MMP and TIMP. Organ cultures were performed using explants from the skin of three patients from the same family with recessive dystrophic epidermolysis bullosa to reveal and quantify the expression of MMP-1 (collagenase 1), MMP-2 and MMP-9 (gelatinases A and B), MMP-3 (stromelysin 1), TIMP-1, and TIMP-2, and to compare the results with those obtained with two human control skins, with the same experimental conditions. Increased amounts of all metalloproteinases investigated were observed in the skin of the three recessive dystrophic epidermolysis bullosa affected sibling brothers, both in lesioned and in apparently nonlesioned skin, compared with controls. The amounts of MMP-1, MMP-2, MMP-3, and MMP-9 increased particularly in the skin of the more clinically affected patient. Furthermore for this patient we evidenced higher amounts of MMP-1 and also a lower TIMP-1 amount in his unlesioned and lesioned skin compared with the other two affected patients and with healthy control donors. So we can suspect that recessive dystrophic epidermolysis bullosa phenotypic variability could be related to patients' collagenase activity heterogeneity, linked to imbalance between MMP-1 and TIMP-1.

Ichthyosis is a heterogeneous group of skin disorders characterized by abnormal epidermal scaling. Occasionally, extracutaneous features are associated. A novel autosomal recessive ichthyosis syndrome is described here with scalp hypotrichosis, scarring alopecia, sclerosing cholangitis, and leukocyte vacuolization in two inbred kindreds of Moroccan origin. We also report the mapping of the diseased gene to a 21.2 cM interval of chromosome 3q27-q28. Homo zygosity for polymorphic markers has enabled us to reduce the genetic interval to a 16.2 cM region. Furthermore, comparison of mutant chromosomes in the two families has suggested a common ancestral mutant haplotype. This linkage disequilibrium has reduced the genetic interval encompassing the diseased gene to less than 9.5 cM maximum. Further study of additional families from the same geographic area will hopefully reduce the genetic interval as well as help in the cloning of the gene involved in this rare disorder.

Netherton syndrome is a severe autosomal recessive skin disorder characterized by congenital erythroderma, a specific hair-shaft abnormality, and atopic manifestations with high IgE levels. Recently, we identified SPINK5, which encodes the serine protease inhibitor Kazal-type 5 protein (LEKTI), as the defective gene in Netherton syndrome. Here we describe the intron-exon organization of the gene and characterize the SPINK5 mutations in patients from 21 families of different geographic origin, using denaturing high performance liquid chromatography and direct sequencing. We identified 18 mutations, of which 13 were novel and seven (39%) were recurrent. The majority of the mutations were clustered between exons 1-8 and exons 21-26. They comprised four nonsense mutations (22%), eight frameshift insertions or deletions (44%), and six splice-site defects (33%). All mutations predict the formation of premature termination codons. Northern blot analysis showed variable reduction of SPINK5 mutant transcript levels, suggesting variable efficiency of nonsense-mediated mRNA decay. Seven patients were homozygotes, eight were compound heterozygotes, and five were heterozygotes with only one identifiable SPINK5 mutation. Five mutations, one of which resulted in perinatal lethal disease in three families, were associated with certain ethnic groups. We also describe 45 intragenic polymorphisms in the patients studied. The clinical features of erythroderma, trichorrhexis invaginata, and atopic manifestations were present in the majority of affected individuals and ichthyosis linearis circumflexa was seen in 12 out of 24 patients. Interfamilial and intrafamilial variation in disease severity was observed, with no clear correlation between mutations and phenotype, suggesting that the degree of severity may be affected by other factors.

Cytokines play a role in alopecia areata. We used immunohistochemical and in situ hybridization studies to demonstrate the persistence of pro-inflammatory as well as apoptotic mechanisms in skin biopsies from patients with chronic alopecia areata. In situ hybridization allows the visualization of the distribution of immunocompetent cells in vivo. We studied skin biopsies from 11 untreated alopecia areata patients and two normal controls. In situ hybridization was performed on frozen sections using 35S-radio-labeled riboprobes, specific for IL-1beta, IL-2, IL-6, INFgamma, and granzyme B mRNA. Immunohistochemistry was carried out using an anti-IL-1beta monoclonal antibody, and a monoclonal antibody directed against the human Fas protein. We demonstrated the presence of cells labeled with IL-1beta, IL-6, INFgamma, and granzyme B antisense probes. Similarly, cells labeled with anti-IL-1beta were found in 10 of 11 cases. The labeled cells were located in the mononuclear peri- and intrafollicular infiltrate. Cells expressing granzyme B were found in close contact with the follicle. Fas positivity was demonstrated in four of four cases at the level of the cytoplasmic membrane of the hair follicle keratinocytes. These results, based on visualizing the labeled cells, demonstrate that pro-inflammatory cytokines are produced by the mononuclear cell infiltrate in close contact with follicles in alopecia areata. Furthermore, they demonstrate for the first time that apoptotic mechanisms involving granzyme B and Fas-Fas ligand pathways may play a major role in the persistence of chronic alopecia areata.

The treatment of acne is based upon simple pathogenic arguments, but needs to be adapted to the type of acne. Patients must always be informed that it is long and difficult and that no significant response will be expected before 2 to 3 months of regular treatment. The authors present the different therapeutic agents and strategies. Isotretinoin should be used only in severe acne after failure of at least 3 months of a well conducted classical treatment and in nodulo-cystic acne; because of its major side effect of teratogenicity its use in adolescent girl's requires pregnancy testings before and during treatment and an effective contraception.

Background: Dermatitis herpetiformis (DH) is a chronic papulovesicular immune-mediated disorder associated with gluten-sensitive enteropathy. We report eight cases in which DH appeared many years after celiac disease (CD) in child., Patients and Methods: The diagnosis of CD was based on histological features of total or subtotal villous atrophy, full remission after withdrawal of gluten from the diet, and eventually circulating antibodies (IgA gliadin, antireticulin and antiendomysium) at the time of diagnosis and their disappearance under gluten-free diet. The diagnosis of DH was made from clinical findings, histological examination of the involved skin and direct immunofluorescence microscopy of normal or perilesional skin. HLA class II typing was performed in five patients. DRB1, DQA1, DQB1 and DBP1 alleles were studied., Results: DH appeared between 3 and 22 years after the initial diagnosis of CD. Five patients did not show at that time any digestive symptoms. In three cases, a break in the gluten-free diet or a recent revival of the normal diet preceded the rash. In only one case, DH appeared while the patient was under gluten-free diet. In three patients, the rash appeared many years after the gluten-free diet had been stopped. Phenotype DR3 and/or DR7 of the celiac disease could be found in four of the five patients studied; three of them were found to bear DQW2. The DR2 allele was not found in any of the five tested patients., Discussion: These eight cases illustrate the absence of precise nosological barrier between gluten-sensitive enteropathy of the DH and that observed in CD. The presence of the DR7 allele, and especially the absence of the DR2 allele, could explain the particularly severe and symptomatic course of the enteropathy in these patients. The delay in the appearance of DH, after a very variable period of normal diet, could correspond to the necessary time for progressive accumulation of IgA (or immune complex IgA-gluten) in the skin after a digestive sensitization to gluten. The preventive role of gluten-free diet is thus probable., Conclusion: CD and DH likely correspond to two different stages of the same disease, thus requiring a prolonged follow-up of both digestive and skin tissues. Long-term eviction of gluten to prevent eventual DH must be balanced with the demand and the cost of such a diet.

There are three components in the treatment of atopic dermatitis: 1) a general treatment (mainly antibiotherapy directed towards Staphylococcus aureus during acute phases), 2) local treatment (local antiseptics, local steroids, emollients), 3) practical advice. In addition, it is of great importance that clear and complete information on the illness should be given to the parents.

Linkage analyses in generalized recessive dystrophic epidermolysis bullosa (RDEB) have implicated the type VII collagen gene (COL7A1), which encodes the major component of anchoring fibrils, and recent identification of COL7A1 mutations has provided direct evidence for COL7A1 defects underlying RDEB. In this study, COL7A1 gene analysis was used to successfully perform first-trimester prenatal diagnosis in six families at risk for recurrence of the disease. In four families, three affected with the most severe variant of RDEB (the Hallopeau-Siemens form, HS-RDEB) and one with generalized nonmutilating RDEB, prenatal diagnosis was established by linkage analysis using polymerase chain reaction-based detection of PvuII and AluI intragenic restriction fragment length polymorphism. In two other HS-RDEB families, prenatal diagnosis was carried out by direct detection of mutations in COL7A1, using denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genomic fragments. Analysis of fetal DNA from chorionic villus biopsy or from amniotic fluid cells showed that the fetus had inherited at least one normal COL7A1 allele in all cases. Therefore, the fetus was predicted to be unaffected in the six pregnancies, and this has been confirmed in the newborn infants. Genotype analysis with COL7A1 polymorphic markers, or direct COL7A1 mutation detection in families at risk for the disease, represent early and rapid diagnostic alternatives to second-trimester evaluation of fetal skin samples, and thus offer a major advance in prenatal diagnosis of this life-threatening form of epidermolysis bullosa.

Inherited epidermolysis bullosa (EB) includes three main types depending on the precise ultrastructural level at which the split responsible for the blistering occurs; 1) simplex EB (SEB) located at the level of the basal cells; 2) junctional EB (JEB) located in the lamina lucida; 3) dystrophic EB (DEB) located in the dermis below the lamina densa at the level of the anchoring fibrils. The authors review the major recent progresses which have led to the identification of the genes and of several molecular defects in these three types, such as: mutations of the genes of keratins 5 and 14 in SEB, molecular defects in the gamma 2 chain gene of nicein/kalinin coding for the anchoring fibrils in JEB, abnormalities of the collagen VII gene coding for the anchoring fibrils in DEB. These data allow to consider a classification of EB based on molecular defects. They also have important consequences for genetic counselling and prenatal diagnosis for the families presenting an affected child.

The systemic long-term corticosteroid treatment administered to kidney graft recipients (KGR) within the framework of the required immunosuppressive therapy induces an atrophy of the skin, from the sixth month onwards. We studied the effect of topical all-trans retinoic acid (0.05%; Galderma Labs.) applied to the forearms of 27 KGR (14 men, 13 women) over a 6-month period. Twenty-four subjects completed the trial. The following results were obtained in the treated forearm versus the untreated forearm (excipient alone): clinically, an increase in skin thickness; by noninvasive techniques, an increase in skin thickness, skin elasticity, skin conductance, and TEWL, and a reduction in the size of the corneocytes. No change in stratum corneum lipid content was observed. A sex-related difference was noted in the response to treatment under our experimental conditions, the female patients responding better. A punch biopsy (4 mm) was performed on both forearms of four patients after the 6-month period. Histologic and ultrastructural examination revealed epidermal and dermal changes evoking increased cellular metabolism in the retinoic acid-treated forearms.