PurposePIK3CA-related overgrowth spectrum (PROS) encompasses a range of debilitating conditions defined by asymmetric overgrowth caused by mosaic activating PIK3CA variants. PIK3CA encodes the p110α catalytic subunit of phosphatidylinositol-3-kinase (PI3K), a critical transducer of growth factor signaling. As mTOR mediates the growth-promoting actions of PI3K, we hypothesized that the mTOR inhibitor sirolimus would slow pathological overgrowth.MethodsThirty-nine participants with PROS and progressive overgrowth were enrolled into open-label studies across three centers, and results were pooled. For the primary outcome, tissue volumes at affected and unaffected sites were measured by dual energy X-ray absorptiometry during 26 weeks of untreated run-in and 26 weeks of sirolimus therapy.ResultsThirty participants completed the study. Sirolimus led to a change in mean percentage total tissue volume of –7.2% (SD 16.0, p = 0.04) at affected sites, but not at unaffected sites (+1.7%, SD 11.5, p = 0.48) (n = 23 evaluable). Twenty-eight of 39 (72%) participants had ≥1 adverse event related to sirolimus of which 37% were grade 3 or 4 in severity and 7/39 (18%) participants were withdrawn consequently.ConclusionThis study suggests that low-dose sirolimus can modestly reduce overgrowth, but cautions that the side-effect profile is significant, mandating individualized risk–benefit evaluations for sirolimus treatment in PROS.

An international advisory group met at the National Institutes of Health in Bethesda, Maryland in 2017, to discuss a new classification system for the ectodermal dysplasias (EDs) that would integrate both clinical and molecular information. We propose the following, a working definition of the EDs building on previous classification systems and incorporating current approaches to diagnosis: EDs are genetic conditions affecting the development and/or homeostasis of two or more ectodermal derivatives, including hair, teeth, nails, and certain glands. Genetic variations in genes known to be associated with EDs that affect only one derivative of the ectoderm (attenuated phenotype) will be grouped as non-syndromic traits of the causative gene (e.g., nonsyndromic hypodontia or missing teeth associated with pathogenic variants of EDA "ectodysplasin"). Information for categorization and cataloging includes the phenotypic features, Online Dedication: We dedicate this article to the late Dr. Carlos Salinas, long-time leader who sought continuous improvement in our understanding and classification of the ectodermal dysplasias.

PurposeWe aimed to identify the genetic cause to a clinical syndrome encompassing hypohidrosis, electrolyte imbalance, lacrimal gland dysfunction, ichthyosis, and xerostomia (HELIX syndrome), and to comprehensively delineate the phenotype.MethodsWe performed homozygosity mapping, whole-genome sequencing, gene sequencing, expression studies, functional tests, protein bioinformatics, and histological characterization in two unrelated families with HELIX syndrome.ResultsWe identified biallelic missense mutations (c.386C>T, p.S131L and c.2T>C, p.M1T) in CLDN10B in six patients from two unrelated families. CLDN10B encodes Claudin-10b, an integral tight junction (TJ) membrane-spanning protein expressed in the kidney, skin, and salivary glands. All patients had hypohidrosis, renal loss of NaCl with secondary hyperaldosteronism and hypokalemia, as well as hypolacrymia, ichthyosis, xerostomia, and severe enamel wear. Functional testing revealed that patients had a decreased NaCl absorption in the thick ascending limb of the loop of Henle and a severely decreased secretion of saliva. Both mutations resulted in reduced or absent Claudin-10 at the plasma membrane of epithelial cells.ConclusionCLDN10 mutations cause a dysfunction in TJs in several tissues and, subsequently, abnormalities in renal ion transport, ectodermal gland homeostasis, and epidermal integrity.

These guidelines for the management of congenital ichthyoses have been developed by a multidisciplinary group of European experts following a systematic review of the current literature, an expert conference held in Toulouse in 2016, and a consensus on the discussions. These guidelines summarize evidence and expert-based recommendations and intend to help clinicians with the management of these rare and often complex diseases. These guidelines comprise two sections. This is part two, covering the management of complications and the particularities of some forms of congenital ichthyosis.

Basal cell carcinoma (BCC), the most common human cancer, results from aberrant activation of the Hedgehog signaling pathway. Although most cases of BCC are sporadic, some forms are inherited, such as Bazex-Dupré-Christol syndrome (BDCS)-a cancer-prone genodermatosis with an X-linked, dominant inheritance pattern. We have identified mutations in the ACTRT1 gene, which encodes actin-related protein T1 (ARP-T1), in two of the six families with BDCS that were examined in this study. High-throughput sequencing in the four remaining families identified germline mutations in noncoding sequences surrounding ACTRT1. These mutations were located in transcribed sequences encoding enhancer RNAs (eRNAs) and were shown to impair enhancer activity and ACTRT1 expression. ARP-T1 was found to directly bind to the GLI1 promoter, thus inhibiting GLI1 expression, and loss of ARP-T1 led to activation of the Hedgehog pathway in individuals with BDCS. Moreover, exogenous expression of ACTRT1 reduced the in vitro and in vivo proliferation rates of cell lines with aberrant activation of the Hedgehog signaling pathway. In summary, our study identifies a disease mechanism in BCC involving mutations in regulatory noncoding elements and uncovers the tumor-suppressor properties of ACTRT1.

This study shows that being overweight with abdominal obesity and being obese is more common in children with psoriasis than in controls. The risk factors are the same as those that affect the French general population, i.e. female sex and having a parent who was overweight. The severity and clinical type of psoriasis do not affect overweight and obesity.

The most common outcome of defective dental morphogenesis in human patients is dental agenesis (absence of teeth). This may affect either the primary or permanent dentition and can range from 5 or fewer missing teeth (hypodontia), 6 or more (oligodontia), to complete absence of teeth (anodontia). Both isolated and syndromic dental agenesis have been reported to be associated with a large number of mutated genes. The aim of this review was to analyze the dental phenotypes of syndromic and nonsyndromic dental agenesis linked to gene mutations. A systematic review of the literature focusing on genes ( MSX1, PAX9, AXIN2, PITX2, WNT10A, NEMO, EDA, EDAR, EDARADD, GREMLIN2, LTBP3, LRP6, and SMOC2) known to be involved in dental agenesis was performed and included 101 articles. A meta-analysis was performed using the dental phenotypes of 522 patients. The total number and type of missing teeth were analyzed for each mutated gene. The percentages of missing teeth for each gene were compared to determine correlations between genotypes and phenotypes. Third molar agenesis was included in the clinical phenotype assessment. The findings show that isolated dental agenesis exists as part of a spectrum of syndromes for all the identified genes except PAX9 and that the pattern of dental agenesis can be useful in clinical diagnosis to identify (or narrow) the causative gene mutations. While third molar agenesis was the most frequent type of dental agenesis, affecting 70% of patients, it was described in only 30% of patients with EDA gene mutations. This study shows that the pattern of dental agenesis gives information about the mutated gene and could guide molecular diagnosis for geneticists.

JEADV AbstractBackground Three biotherapiesetanercept, adalimumab and ustekinumabare licensed in childhood psoriasis. The few data available on their efficacy and tolerance are mainly derived from industry trials. However, biological drug survival impacts long-term performance in real-life settings.Objective The objective of this study was to evaluate the survival rates of biological therapies in children with psoriasis in real-life conditions. Secondary objectives were to evaluate the factors associated with the choice of the biological therapy and to report severe adverse events. Materials and methodsThis study was an observational retrospective study. Data were extracted from the clinical records of 134 children. Kaplan-Meier estimates were used to analyse drug survival overall and in subgroups of plaque psoriasis, bio-na€ ıve and non-na€ ıve patients. ResultsWe analysed 184 treatment courses: 70 with etanercept, 68 with adalimumab and 46 with ustekinumab.Factors associated with the choice of first-line biological agent were age at initiation (younger for adalimumab, P < 0.0001), age at onset of psoriasis (younger for adalimumab and etanercept, P = 0.03) and baseline Psoriasis Assessment Severity Index and Physician global assessment (both higher for adalimumab, P < 0.001). Drug survival rates were higher for ustekinumab than for adalimumab and etanercept (P < 0.0001) for all treatment and all psoriasis types, plaque-type psoriasis (P = 0.0003), patients na€ ıve for biological agents (P = 0.0007) and non-na€ ıve patients (P = 0.007). We reported eight serious adverse events (SAEs): severe infections (n = 3), significant weight gain (n = 2), psoriasis flare (n = 1) and malaise (n = 1). Biological therapy was discontinued in three children (one with psoriasis flare and two with weight gain). Only the two cases of weight gain resulted in an unfavourable outcome.Conclusions Our real-life comparative study found that ustekinumab had the best drug survival outcome. The profile of SAEs in children was comparable to that in adults. These results will assist dermatologists in the decision-making process when choosing treatment options for children with psoriasis in daily practice.