Ectodermal dysplasias: a new clinical-genetic classification

A Novel Ectodysplasin a Gene mutation of X-Linked Hypohidrotic Ectodermal Dysplasia

Introduction

Hypohidrotic ectodermal dysplasia (HED) is a genetic disorder that influences structures of ectodermal origin, such as teeth, hair, and sweat glands. Compared with autosomal recessive and dominant modes of inheritance, the X-linked HED (XLHED) characterized by Hypodontia/Oligodontia teeth, Absent/sparse hair, Anhidrosis/hypohidrosis, and characteristic facial features, is the most frequent and its primary cause is the mutation of ectodysplasin A (EDA) gene. This research aimed to expound the clinical and molecular features of a Chinese male with XLHED and to summarize and compare several previous findings.

Methods

Genomic DNA was obtained from the peripheral blood of the proband and his family members, then Sanger sequencing was used to perform a mutational analysis of EDA. Real-time quantitative PCR and Western blotting were used to detect EDA expression. The transcriptional activity of NF-κB was detected using a luciferase assay.

Results

The probandwith XLHED was identified a novel EDA mutation, c.1119G>C(p.M373I), that affected the molecular analysis of transmembrane protein exon8 mutations, inherited from the mother. He showed a severe multiple-tooth loss, with over 20 permanent teeth missing and sparse hair and eyebrows, dry, thin, and itching skin. Furthermore, his sweating function was abnormal to a certain extent.

Discussion

The functional study showed that this novel mutant led to a significant decrease in the EDA expression level and transcriptional activity of NF-κB. Our findings extend the range of EDA mutations in XLHED patients, which provides the basis and idea for further exploring the pathogenesis of XLHED.

Hair Evaluation in Orthodontic Patients with Oligodontia

Oligodontia can be isolated or syndromic, associated with other ectodermal abnormalities. The aim of the study was to perform hair examination in orthodontic patients diagnosed with oligodontia with a low clinical expression of symptoms of ectodermal origin. All available orthodontic patients diagnosed with oligodontia in the permanent dentition were enrolled. Hair examination included clinical evaluation of the patients' hair, trichoscopy, trichogram and evaluation of the hair shafts under a polarized light microscope. In total, 25 patients, 18 males and 7 females, aged 6 to 24 years were evaluated for the presence of dental and hair abnormalities. The number of congenitally absent teeth ranged from 6 to 24 teeth and diastemas, microdontia, taurodontism and altered tooth shape were found in 23 patients. Hair disorders were found in 68% of the subjects. Hypotrichosis, the heterogeneity of shaft color and loss of pigment, androgenetic alopecia, telogen effluvium, trichoschisis, pili canaliculi, trichorrhexis nodosa and pseudomoniletrix were observed. Trichoscopy and trichogram are valid non-invasive diagnostic tests which could be used to differentiate between isolated and syndromic oligodontia in patients with a low clinical expression of ectodermal symptoms.

Heterozygous MAP3K20 variants cause ectodermal dysplasia, craniosynostosis, sensorineural hearing loss, and limb anomalies

Biallelic pathogenic variants in MAP3K20, which encodes a mitogen-activated protein kinase, are a rare cause of split-hand foot malformation (SHFM), hearing loss, and nail abnormalities or congenital myopathy. However, heterozygous variants in this gene have not been definitively associated with a phenotype. Here, we describe the phenotypic spectrum associated with heterozygous de novo variants in the linker region between the kinase domain and leucine zipper domain of MAP3K20. We report five individuals with diverse clinical features, including craniosynostosis, limb anomalies, sensorineural hearing loss, and ectodermal dysplasia-like phenotypes who have heterozygous de novo variants in this specific region of the gene. These individuals exhibit both shared and unique clinical manifestations, highlighting the complexity and variability of the disorder. We propose that the involvement of MAP3K20 in endothelial-mesenchymal transition provides a plausible etiology of these features. Together, these findings characterize a disorder that both expands the phenotypic spectrum associated with MAP3K20 and highlights the need for further studies on its role in early human development.

Activation of wnt/β-catenin signaling pathway down regulated osteogenic differentiation of bone marrow-derived stem cells in an anhidrotic ectodermal dysplasia patient with EDA/EDAR/EDARADD mutation

Objective

To explore the mechanism by which the Wnt/β-catenin pathway induces osteogenic differentiation of bone marrow-derived stem cells (BMSCs) in anhidrotic ectodermal dysplasia (AED) with an Ectodysplasin A (EDA)/EDA receptor (EDAR)/EDARADD mutation.

Methods

An AED patient served as the AED group, whereas the other patients without AED were included in the normal group. Peripheral venous blood collected from the AED patient was subjected to whole-genome resequencing. BMSCs from the mandible of patients with AED and normal individuals were isolated and cultured in vitro. Cell proliferation assay was performed to compare the growth speed of BMSCs between the AED and normal groups. CHIR-99021, an activator of the Wnt/β-catenin pathway and XAV-939, an inhibitor, was used to manage BMSCs in an osteogenic environment in both groups. The expression of β-catenin was detected by quantitative polymerase chain reaction, while that of RUNX2 was detected by western blotting. Alizarin red was used for staining.

Results

A novel mutation (c.152T > A in EDA) and two known mutations (c.1109T > C in EDAR and c.27G > A in EDARADD) were identified. The growth rate in the normal group was higher than that in the AED group. In the normal group, the number and size of calcified nodes and the expression of RUNX-2 increased with CHIR-99021 treatment, which could be inhibited by XAV-939. In contrast, CHIR-99021 inhibited osteogenesis in the AED group and this effect was promoted by XAV-939.

Conclusion

Activation of the Wnt/β-catenin pathway downregulates osteogenesis of BMSCs in AED patients with EDA/EDAR/EDARADD gene mutations. Further investigation in more AED patients is required, given the wide range of mutations involved in AED.

Intubation in a Case of Ectodermal Dysplasia During Surgery: A Case Report

Ectodermal dysplasia, a heterogeneous group of rare genetic disorders, is characterized by the aberrant development of ectodermal structures, leading to various clinical anomalies. This case report presents a unique and challenging case of a 33-year-old male with ectodermal dysplasia who underwent Le Fort III advancement and implant rehabilitation surgery to address severe craniofacial and dental deficiencies. This case, characterized by facial dysmorphism, craniofacial anomalies, and the absence of a nasal bone, highlights the complexity of surgical planning required to address these diverse clinical features. The crucial element of this report is the innovative approach to airway management through trans mylohyoid/submental intubation, which successfully navigated the patient's aberrant anatomy. Multidisciplinary collaboration played a pivotal role in achieving a holistic and patient-centered approach. By sharing this case, we aim to provide insights into the nuances of managing complex patients with ectodermal dysplasia, emphasizing the importance of individualized care, innovative techniques, and interdisciplinary teamwork to optimize patient outcomes and contribute to advancing medical knowledge.

Novel mutations in genes of the IL-12/IFN-γ axis cause susceptibility to tuberculosis

BACKGROUND

The IL-12/23/ISG15-IFN-γ pathway is the main immunological pathway for controlling intra-macrophagic microorganisms such as Mycobacteria, Salmonella, and Leishmania spp. Consequently, upon mutations in genes of the IL-12/23/ISG15-IFN-γ pathway cause increased susceptibility to intra-macrophagic pathogens, particularly to Mycobacteria. Therefore, the purpose of this study was to characterize the mutations in genes of the IL-12/23/ISG15-IFN-γ pathway in severe tuberculosis (TB) patients.

METHODS

Clinically suspected TB was initially confirmed in four patients (P) (P1, P2, P3, and P4) using the GeneXpert MTB/RIF and culturing techniques. The patients' Peripheral blood mononuclear cells (PBMCs) were then subjected to ELISA to measure Interleukin 12 (IL-12) and interferon gamma (IFN-γ). Flow cytometry was used to detect the surface expressions of IFN-γR1 and IFN-γR2 as well as IL-12Rβ1and IL-12Rβ2 on monocytes and T lymphocytes, respectively.The phosphorylation of signal transducer and activator of transcription 1(STAT1) on monocytes and STAT4 on T lymphocytes were also detected by flow cytometry. Sanger sequencing was used to identify mutations in the IL-12Rβ1, STAT1, NEMO, and CYBB genes.

RESULTS

P1's PBMCs exhibited reduced IFN-γ production, while P2's and P3's PBMCs exhibited impaired IL-12 induction. Low IL-12Rβ1 surface expression and reduced STAT4 phosphorylation were demonstrated by P1's T lymphocytes, while impaired STAT1 phosphorylation was detected in P2's monocytes. The impaired IκB-α degradation and abolished H2O2 production in monocytes and neutrophils of P3 and P4 were observed, respectively. Sanger sequencing revealed novel nonsense homozygous mutation: c.191 G>A/p.W64 * in exon 3 of the IL-12Rβ1 gene in P1, novel missense homozygous mutation: c.107 A>T/p.Q36L in exon 3 of the STAT1 gene in P2, missense hemizygous mutation:: c.950 A>C/p.Q317P in exon 8 of the NEMO gene in P3, and nonsense hemizygous mutation: c.868 C>T/p.R290X in exon 8 of CYBB gene in P4.

CONCLUSION

Our findings broaden the clinical and genetic spectra associated with IL-12/23/ISG15-IFN-γ axis anomalies. Additionally, our data suggest that TB patients in Pakistan should be investigated for potential genetic defects due to high prevalence of parental consanguinity and increased incidence of TB in the country.

Establishing an objective clinical spectrum, genotype-phenotype correlations, and CRMP1 as a modifier in the Ellis-van Creveld syndrome: The first systematic review of EVC- and EVC2-associated conditions

Purpose

Ellis-van Creveld (EVC) syndrome is an autosomal recessive skeletal ciliopathy that was first identified in the Old Order Amish. Since its discovery, two causal genes have been identified, EVC and EVC2, showing that several cases were misdiagnosed and were, in fact, other entities. Nevertheless, there has not been any adequate phenotypic characterization of molecularly defined EVC syndrome so far.

Methods

We performed a systematic review of case reports of EVC syndrome with molecular confirmation of pathogenic variants in EVC or EVC2. Demographic, genetic, and clinical information of patients was assessed.

Results

We reviewed 725 papers and obtained 54 case reports/series that met the inclusion criteria, with a total subject sample of 310. Of these, 190 had biallelic variants, whereas 28 were affected heterozygotes. Our analysis revealed new phenotypes that have not been classically linked to the syndrome and others that have been linked but are very rare. Monoallelic symptomatic forms had less expressivity, and biallelic cases were milder if associated with EVC and/or missense variants. Finally, we identified CRMP1, a gene whose coding region partially overlaps with EVC, as a potential genetic modifier of the severity of the EVC syndrome.

Conclusion

We provided the first objective clinical characterization of molecularly defined EVC syndrome and identified the first associated genetic modifier, CRMP1, which had not been implicated in human disease before.

Hypohidrotic ectodermal dysplasia: a case report

Hypohidrotic ectodermal dysplasia (HED) is a rare heterogeneous genetic congenital disorder affecting at least 1 in 5000-10,000 newborns. This disorder has a wide range of clinical manifestations; it affects organs originating from the embryonic ectoderm.

Case presentation

We present a case of a 2-year-old boy diagnosed with HED, the boy was suffering from absence of sweating since birth, dry skin, recurrent episodes of hyperpyrexia, sparse and light-colored hair on the scalp, absent eyebrows, and delayed eruption of abnormally shaped teeth.

Clinical discussion

The are no diagnostic criteria guidelines for HED, we diagnosed the disorder by the clinical manifestations and the family history. The management of patients with HED is palliative.

Conclusion

This disorder needs multidisciplinary contribution to improve the general health of those patients, quality of life, and decrease morbidity and mortality.

Extended Overview of Ocular Phenotype with Recent Advances in Hypohidrotic Ectodermal Dysplasia

The term ectodermal dysplasias (EDs) describes a heterogeneous group of inherited developmental disorders that affect several tissues of ectodermal origin. The most common form of EDs is hypohidrotic ectodermal dysplasia (HED), which is characterized by hypodontia, hypotrichosis, and partial or total eccrine sweat gland deficiency. HED is estimated to affect at least 1 in 17,000 people worldwide. Patients with HED have characteristic facies with periorbital hyperpigmentation, depressed nasal bridge, malar hypoplasia, and absent or sparse eyebrows and eyelashes. The common ocular features of HED include madarosis, trichiasis, and ocular chronic surface disease due to dry eye syndrome, which manifests clinically with discomfort, photophobia, and redness. Dry eye is common in HED and results from a combination of ocular surface defects: mucus abnormalities (abnormal conjunctival mucinous glands), aqueous tear deficiency (abnormalities in the lacrimal gland) and lipid deficiency (due to the partial or total absence of the meibomian glands; modified sebaceous glands with the tarsal plate). Sight-threatening complications result from ocular surface disease, including corneal ulceration and perforation with subsequent corneal scarring and neovascularization. Rare ocular features have been reported and include bilateral or unilateral congenital cataracts, bilateral glaucoma, chorioretinal atrophy and atresia of the nasolacrimal duct. Recognition of the ocular manifestations of HED is required to perform clinical surveillance, instigate supportive and preventative treatment, and manage ocular complications.

Confirmation of a Phenotypic Entity for TSPEAR Variants in Egyptian Ectodermal Dysplasia Patients and Role of Ethnicity

Ectodermal dysplasia (ED) are hereditary disorders characterized by the disturbance of the ectodermal development of at least two of four ectodermal tissues: teeth, hair, nails and sweat glands. Clinical classification of ED is challenged by overlapping features, variable expressivity, and low number of patients, hindering full phenotypic spectrum identification. Disease-causing variants in elements of major developmental pathways, e.g., Ectodysplasin/NFκB, Wnt, and Tp63 pathways, have been identified in fewer than half of ED phenotypes. Whole-exome sequencing (WES) was performed for ten Egyptian ED patients presenting with tooth agenesis, normal sweating, scalp hypotrichosis, and sharing characteristic facial features. WES was followed by in silico analysis of the effects of novel detected genetic variants on mRNA and protein structure. The study identified four novel rare pathogenic and likely pathogenic TSPEAR variants, a gene which was recently found to be involved in ectodermal organogenesis. A novel in-frame deletion recurred in eight patients from six unrelated families. Comparing our cohort to previously reported TSPEAR cohorts highlighted the influence of ethnicity on TSPEAR phenotypic affection. Our study expands the clinical and mutational spectrum of the growing TSPEAR associated phenotypes, and pinpoints the influence of WES and in silico tools on identification of rare disease-causing variants.

Non-Plaque Induced Diffuse Gingival Overgrowth: An Overview

Non-plaque induced diffuse gingival overgrowth represents a broad class of conditions caused by several etiological factors. The aim of this review is to highlight the most recent updates and classifications of all the existent gingival overgrowths. In addition, we highlighted the diagnostic pathway that should be employed in patients affected by gingival overgrowth. Gingival overgrowth can be related to syndromic diseases including a wide spectrum of genetic and chromosomal alterations. However, thanks to scientific sharing and the availability of genetic panels it is possible to obtain an accurate phenotypic identification of well-known syndromes and also to identify new ones. This narrative review shows that through rigid, strict diagnostic protocols, the work of the clinician is greatly facilitated, despite the wide variety of pathologies considered. In conclusion, the exchange of specialists’ competencies and the multidisciplinary management of these patients, are crucial to reach diagnosis and the correct clinical-therapeutic management.

Clinical and genetic characteristics of ectodermal dysplasia in four Indian children

Introduction:

Ectodermal dysplasias (EDs) affect structures derived from the ectoderm such as skin, its appendages, nail, and teeth. In this series, we describe four patients presenting with a clinical phenotype of dysplasia of one or more ectodermal structures who underwent next-generation sequencing for mutational analysis.

Case Series:

The clinical phenotype of three patients was hypohidrotic ectodermal dysplasia (HED) and one patient was diagnosed with autoimmune polyglandular syndrome (APS) type 1. Two patients with classical clinical features of X-linked HED (XLHED) had mutations in EDA gene; variant c.924+ 8C>G (5′ proximal splice site) and c.760C>T (p.Gln254Ter). Case 3 had clinical phenotype of HED with urticaria pigmentosa, which was confirmed on skin biopsy and immunohistochemistry. This patient was found to have mutation in C1orf172; c.449G>A (p.Arg150Gln) which has not been reported previously. Case 4 was diagnosed to have APS type 1 with cutaneous features of discoloration of teeth and chronic mucocutaneous candidiasis. This patient had a compound heterozygous mutation of AIRE gene. The two variants detected were c.169C>T (p.Gln57Ter) and c.47C>T (p.Thr16Met).

Conclusion:

The present series highlights the clinic-genetic correlation in four patients with features of ED. Two variants of uncertain significance and two previously unreported variants were also found in this study.

Two novel ectodysplasin A gene mutations and prenatal diagnosis of X-linked hypohidrotic ectodermal dysplasia

Background

Hypohidrotic ectodermal dysplasia (HED) is mainly caused by ectodysplasin A (EDA) gene mutation. Fetus with genetic deficiency of EDA can be prenatally corrected. This study aimed at revealing the pathogenesis of two HED families and making a prenatal diagnosis for one pregnant female carrier.

Designs

Genomic DNA was extracted from two HED patients and sequenced using whole exome sequencing (WES). The detected mutations were confirmed in patients and family members using Sanger sequencing. The expression of soluble ectodysplasin A1 (EDA1) protein was studied by western blot. The transcriptional activity of NF‐κB pathway was tested by dual luciferase assay. The genomic DNA of fetus was extracted from shed chorion cells and EDA gene was screened through Sanger sequencing.

Results

We identified two novel EDA mutations: c.1136T>C (p.Phe379Ser) and c.[866G>C;868A>T] (p.[Arg289Pro;Ser290Cys]). Further examinations revealed that these two mutated EDA1 proteins showed completely impaired solubility, and the transcriptional NF‐κB activation induced by these missense mutant‐type EDA1 proteins was significantly reduced compared with wild‐type EDA1. Furthermore, the analysis of amniotic fluid samples from a pregnant heterozygote indicated that the fetus was a c.1136T>C mutation female carrier.

Conclusions

This study extended the mutation spectrum of X‐linked hypohidrotic ectodermal dysplasia (XLHED) and applied prenatal diagnosis for the pregnant carrier, which can be helpful in genetic counseling, prenatal diagnosis, and intervention for the XLHED family.

Anhydrotic Ectodermal Dysplasia – A Cause of Prolonged Fever in Infant

Ectodermal dysplasia is a group of conditions characterized by abnormal development of ectodermal tissues including the skin, hair, teeth and sweat glands. Anhidrotic ectodermal dysplasia (Christ-Siemens-Touraine Syndrome) is only one of this large and heterogenous group, but is the most frequent. An inability to sweat (anhidrosis) can lead to high body temperature (hyperthermia), because the body cannot cool itself by evaporating sweat. The authors present the diagnostic difficulties in an infant with this condition, in which prolonged fever was the dominant symptom.

First report of X-linked hypohidrotic ectodermal dysplasia with a hemizygous c.1142G > C in the EDA gene: variant of uncertain significance or new pathogenic variant?

Background

Hypohidrotic Ectodermal Dysplasia (HED) is a genetic disorder which affects structures of ectodermal origin. X-linked hypohidrotic ectodermal dysplasia (XLHED) is the most common form of disease. XLHED is characterized by hypotrichosis, hypohydrosis and hypodontia. The cardinal features of classic HED become obvious during childhood.

Identification of a hemizygous EDA pathogenic variant in an affected male confirms the diagnosis.

Case presentation

We report on a male newborn with the main clinical characteristics of the X-linked HED including hypotrichosis, hypodontia and hypohidrosis. Gene panel sequencing identified a new hemizygous missense variant of uncertain significance (VUS) c.1142G > C (p.Gly381Ala) in the EDA gene, located on the X chromosome and inherited from the healthy mother.

Conclusion

Despite the potential functional impact of VUS remains uncharacterized, our goal is to evaluate the clinical potential consequences of missense VUS on EDA gene. Even if the proband’s phenotype is characteristic for classic HED, further reports of patients with same clinical phenotype and the same genomic variant are needed to consider this novel VUS as responsible for the development of HED.

Interdisciplinary rehabilitation of a patient with ectodermal dysplasia utilizing digital tools: A clinical report

The present clinical report describes the rehabilitation of a patient diagnosed with ectodermal dysplasia performed by an interdisciplinary team in a comprehensive approach aided by digital technology. The complexity of the treatment was related to predictability regarding timing and the type of approach. The patient was referred for treatment because of congenitally missing and abnormally shaped permanent teeth. The need for an interdisciplinary team involving orthodontic, periodontic, and prosthodontic specialists was identified. A virtual treatment plan was developed to guide tooth movement, placement of dental implants, and tooth preparation for indirect restorations. Therefore, each treatment phase could be communicated to the patient and treatment team in a predictable way.

A novel EDA1 missense mutation in X-linked hypohidrotic ectodermal dysplasia

A mutation in the epithelial morphogen gene ectodysplasin-A1 (EDA1) is responsible for the disorder X-linked hypohidrotic ectodermal dysplasia (XLHED), the most common form of ectodermal dysplasia. XLHED is characterized by impaired development of hair, eccrine sweat glands, and teeth. This study aimed to identify potentially pathogenic mutations in four Chinese XLHED families.Genomic DNA was extracted from the peripheral blood and sequenced. Sanger sequencing was used to carry out mutational analysis of the EDA1 gene, and the three-dimensional structure of the novel mutant residues in the EDA trimer was determined. Transcriptional activity of NF-κB was tested by Dual luciferin assay.We identified a novel EDA1 mutation (c.1046C>T) and detected 3 other previously-reported mutations (c.146T>A; c.457C>T; c.467G>A). Our findings demonstrated that novel mutation c.1046C>T (p.A349 V) resulted in XLHED. The novel mutation could cause volume repulsion in the protein due to enlargement of the amino acid side chain. Dual luciferase assay revealed that transcriptional NF-κB activation induced by XLHED EDA1 protein was significantly reduced compared with wild-type EDA1.These results extend the spectrum of EDA1 mutations in XLHED patients and suggest a functional role of the novel mutation in XLHED.

The characterization of hypodontia, hypohidrosis, and hypotrichosis associated with X-linked hypohidrotic ectodermal dysplasia: A systematic review

The objective of this study was to review the published literature on X-linked hypohidrotic ectodermal dysplasia (XLHED) for the prevalence and characteristics of three features of XLHED: hypodontia, hypohidrosis, and hypotrichosis. A systematic search of English-language articles was conducted in May 2019 to identify publications with information on any of the three features of XLHED. We excluded studies with five or fewer participants, that did not specify X-linked inheritance or an EDA mutation, and discussed only management of features. The weighted means for total missing teeth, location of missing teeth, prevalence of reduced and absent sweating ability, and sparse or absent hair were analyzed across all studies. Additional findings for hypodontia, hypohidrosis, and hypotrichosis were summarized qualitatively. Twenty publications (18 studies) were accepted. Reported findings for males tended to be more informative than for carrier females. The weighted mean for missing teeth for affected males was 22.4 (range: 10-28) and carrier females was 3.4 (range: 0-22). The most common conserved teeth for males were the canines. The most common missing teeth for females were the maxillary lateral incisors. The weighted mean prevalence of reduced or absent sweating ability was 95.7% for males and 71.6% for females. The weighted mean prevalence for hypotrichosis was 88.1% for males and 61.6% for females. This systematic review provides insight into the prevalence, characteristics, and variability of the three classic features of XLHED. These findings provide detailed natural history information for families with XLHED as well as key characteristics that can aid in diagnosis.

Ectodermal dysplasias: Classification and organization by phenotype, genotype and molecular pathway

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., non-syndromic hypodontia or missing teeth associated with pathogenic variants of EDA "ectodysplasin"). Information for categorization and cataloging includes the phenotypic features, Online Mendelian Inheritance in Man number, mode of inheritance, genetic alteration, major developmental pathways involved (e.g., EDA, WNT "wingless-type," TP63 "tumor protein p63") or the components of complex molecular structures (e.g., connexins, keratins, cadherins).

Defective NaCl Reabsorption in Salivary Glands of Eda-Null X-LHED Mice

Mutations in the ectodysplasin A gene ( EDA) cause X-LHED (X-linked hypohidrotic ectodermal dysplasia), the most common human form of ectodermal dysplasia. Defective EDA signaling is linked to hypoplastic development of epithelial tissues, resulting in hypotrichosis, hypodontia, hypohidrosis, and xerostomia. The primary objective of the present study was to better understand the salivary gland dysfunction associated with ectodermal dysplasia using the analogous murine disorder. The salivary flow rate and ion composition of the 3 major salivary glands were determined in adult Eda-deficient Tabby hemizygous male (Ta/Y) and heterozygous female (Ta/X) mice. Submandibular and sublingual glands of Eda-mutant mice were smaller than wild-type littermates, while parotid gland weight was not significantly altered. Fluid secretion by the 3 major salivary glands was essentially unchanged, but the decrease in submandibular gland size was associated with a dramatic loss of ducts in Ta/Y and Ta/X mice. Reabsorption of Na+ and Cl-, previously linked in salivary glands to Scnn1 Na+ channels and Cftr Cl- channels, respectively, was markedly reduced at high flow rates in the ex vivo submandibular glands of Ta/Y mice (~60%) and, to a lesser extent, Ta/X mice (Na+ by 14%). Consistent with decreased Na+ reabsorption in Ta/Y mice, quantitative polymerase chain reaction analysis detected decreased mRNA expression for Scnn1b and Scnn1g, genes encoding the β and γ subunits, respectively. Moreover, the Na+ channel blocker amiloride significantly inhibited Na+ and Cl- reabsorption by wild-type male submandibular glands to levels comparable to those observed in Ta/Y mice. In summary, fluid secretion was intact in the salivary glands of Eda-deficient mice but displayed marked Na+ and Cl- reabsorption defects that correlated with the loss of duct cells and decreased Scnn1 Na+ channel expression. These results provide a likely mechanism for the elevated NaCl concentration observed in the saliva of affected male and female patients with X-LHED.

A novel splicing mutation of ectodysplasin A gene responsible for hypohidrotic ectodermal dysplasia

Hypohidrotic ectodermal dysplasia (HED) is characterized by hypohidrosis, hypodontia, sparse hair, and characteristic facial features. This condition is caused by an ectodysplasin A (EDA) gene mutation. In this study, we examined two HED pedigrees and investigated the molecular genetics of the defect. Direct sequencing analysis revealed a previously unidentified mutation in the EDA splice donor site (c.526 + 1G>A). The function of the mutant EDA gene was predicted through online investigations and subsequently confirmed by splicing analysis in vitro. The mutation resulted in the production of a truncated EDA-A1 protein caused by complete omission of exon 3. This novel functional skipping-splicing EDA mutation was considered to be the cause of HED in the two pedigrees reported here. Our findings, combined with those reported elsewhere, provide an improved understanding of the pathogenic mechanism of HED as well as important information for a genetic diagnosis.

Hypohidrotic ectodermal dysplasia: clinical and molecular review

Hypohidrotic Ectodermal Dysplasia (HED) is a genetic human disorder which affects structures of ectodermal origin. Although there are autosomal recessive and dominant forms, X-linked (XL) is the most frequent form of the disease. This XL-HED phenotype is associated with mutations in the gene encoding the transmembrane protein ectodysplasin-1 (EDA1), a member of the TNFα-related signaling pathway. The proteins from this pathway are involved in signal transduction from ectoderm to mesenchyme leading to the development of ectoderm-derived structures in the fetus such as hair, teeth, skin, nails, and eccrine sweat glands. The aim of this review was to update the main clinical characteristics of HED regarding to recent molecular advances in the comprehension of all the possible genes involved in this group of disorders since it is known that Eda-A1-Edar signaling has multiple roles in ectodermal organ development, regulating their initiation, morphogenesis, and differentiation steps. The knowledge of the biological mechanisms that generate HED is needed for both a better detection of possible cases and for the design of efficient prevention and treatment approaches.

Soft Tissue Facial Angles in Individuals with Ectodermal Dysplasia: A Three-Dimensional Noninvasive Study

Objective

To supply quantitative information about the facial soft tissues of patients with hypohidrotic ectodermal dysplasia.

Design

Prospective assessment.

Setting

National meetings of hypohidrotic ectodermal dysplasia patients and families.

Patients and Main Outcome Measures

Facial and mandibular corpus convexities in the horizontal plane; facial convexity in the sagittal plane; interlabial, naso-labial, nasal convexity, and left and right soft tissue gonial angles were calculated from the three-dimensional coordinates of 11 soft tissue facial landmarks obtained in 18 male and 17 female hypohidrotic ectodermal dysplasia patients aged 3 to 41 years and in 504 reference healthy individuals. In addition, z-scores were computed and the patients were grouped by cluster analysis.

Results

Male and female z-scores did not differ. In the pooled group, facial convexities in the horizontal and sagittal planes were significantly (Student's t, p < .01) increased (flatter) in hypohidrotic ectodermal dysplasia patients, compared with normal controls. The naso-labial angle was significantly reduced (more acute). Upper and lower facial convexity and mandibular corpus convexity in the horizontal plane deviated less from the norm with increasing age. Facial convexity in the horizontal and sagittal planes, soft tissue gonial angles, and naso-labial and interlabial angles deviated less from the norm with increasing number of teeth present in the mouth. Cluster analysis identified three homogeneous groups, all characterized by a peculiar facial phenotype. Modifications in facial convexity and gonial and interlabial angles differentiated each cluster.

Conclusions

Patients with hypohidrotic ectodermal dysplasia had flatter faces in the horizontal and sagittal planes than normal controls had. Cluster analysis revealed patterned differences in facial phenotype.

Mutation detection and prenatal diagnosis of XLHED pedigree

BACKGROUND

The phenotypic characters of X -linked Hypohidrotic Ectodermal Dysplasia (XLHED) are the dysplasia of epithelial- and mesenchymal-derived organs. Ectodysplasin (EDA) is the causative gene of XLHED.

METHODS

The current study reported a large Chinese XLHED pedigree. The genomic DNA of adult and fetus was extracted from peripheral blood and shed chorion cell respectively. The nucleotide variation in EDA gene was screened through direct sequencing the coding sequence. The methylation state of EDA gene's promoter was evaluated by pyrosequencing.

RESULTS

This Chinese XLHED family had two male patients and three carriers. All of them were with a novel EDA frameshift mutation. The mutation, c.172-173insGG, which leads to an immediate premature stop codon in exon one caused severe structural changes of EDA. Prenatal diagnosis suggested that the fetus was a female carrier. The follow-up observation of this child indicated that she had mild hypodontia of deciduous teeth at age six. The methylation level of EDA gene's promoter was not related to carriers' phenotype changes in this family.

DISCUSSION

We reported a new frameshift mutation of EDA gene in a Chinese family. Prenatal diagnosis can help to predict the disease status of the fetus.

Mutational spectrum in 101 patients with hypohidrotic ectodermal dysplasia and breakpoint mapping in independent cases of rare genomic rearrangements

Hypohidrotic ectodermal dysplasia (HED), a rare and heterogeneous hereditary disorder, is characterized by deficient development of multiple ectodermal structures including hair, sweat glands and teeth. If caused by mutations in the genes EDA, EDA1R or EDARADD, phenotypes are often very similar as the result of a common signaling pathway. Single-nucleotide polymorphisms (SNPs) affecting any gene product in this pathway may cause inter- and intrafamilial variability. In a cohort of 124 HED patients, genotyping was attempted by Sanger sequencing of EDA, EDA1R, EDARADD, TRAF6 and EDA2R and by multiplex ligation-dependent probe amplification (MLPA). Pathogenic mutations were detected in 101 subjects with HED, affecting EDA, EDA1R and EDARADD in 88%, 9% and 3% of the cases, respectively, and including 23 novel mutations. MLPA revealed exon copy-number variations in five unrelated HED families (two deletions and three duplications). In four of them, the genomic breakpoints could be localized. The EDA1R variant rs3827760 (p.Val370Ala), known to lessen HED-related symptoms, was found only in a single individual of Asian origin, but in none of the 123 European patients. Another SNP, rs1385699 (p.Arg57Lys) in EDA2R, however, appeared to have some impact on the hair phenotype of European subjects with EDA mutations.

Ectodermal Dysplasia: A Clinical Overview for the Dental Practitioner

The term ectodermal dysplasia (ED) is used to describe a group of rare congenital disorders characterized by abnormalities of two or more ectodermal structures such as the skin, hair, nails, teeth and sweat glands. This paper will give an overview of the aetiology of ED and describe the manifestations and dental management of this condition. In particular, the important role of the dental practitioner in the identification and management of patients with ED will be highlighted. CPD/Clinical Relevance: Dental practitioners should be aware of the oral features of ectodermal dysplasia and be able to make timely referrals and provide appropriate continuing care for these patients.

The homeoprotein DLX3 and tumor suppressor p53 co-regulate cell cycle progression and squamous tumor growth

Epidermal homeostasis depends on the coordinated control of keratinocyte cell cycle. Differentiation and the alteration of this balance can result in neoplastic development. Here we report on a novel DLX3-dependent network that constrains epidermal hyperplasia and squamous tumorigenesis. By integrating genetic and transcriptomic approaches, we demonstrate that DLX3 operates through a p53-regulated network. DLX3 and p53 physically interact on the p21 promoter to enhance p21 expression. Elevating DLX3 in keratinocytes produces a G1-S blockade associated with p53 signature transcriptional profiles. In contrast, DLX3 loss promotes a mitogenic phenotype associated with constitutive activation of ERK. DLX3 expression is lost in human skin cancers and is extinguished during progression of experimentally induced mouse squamous cell carcinoma (SCC). Reinstatement of DLX3 function is sufficient to attenuate the migration of SCC cells, leading to decreased wound closure. Our data establish the DLX3-p53 interplay as a major regulatory axis in epidermal differentiation and suggest that DLX3 is a modulator of skin carcinogenesis.

Molecular basis of hypohidrotic ectodermal dysplasia: an update

Recent advances in understanding the molecular events underlying hypohidrotic ectodermal dysplasia (HED) caused by mutations of the genes encoding proteins of the tumor necrosis factor α (TNFα)-related signaling pathway have been presented. These proteins are involved in signal transduction from ectoderm to mesenchyme during development of the fetus and are indispensable for the differentiation of ectoderm-derived structures such as eccrine sweat glands, teeth, hair, skin, and/or nails. Novel data were reviewed and discussed on the structure and functions of the components of TNFα-related signaling pathway, the consequences of mutations of the genes encoding these proteins, and the prospect for further investigations, which might elucidate the origin of HED.

Generation of Evc2/Limbin global and conditional KO mice and its roles during mineralized tissue formation

Ellis-van Creveld (EvC) syndrome (OMIM 225500) is an autosomal recessive disease characterized with chondrodysplastic dwarfism in association with abnormalities in oral cavity. Ciliary proteins EVC and EVC2 have been identified as causative genes and they play an important role on Hedgehog signal transduction. We have also identified a causative gene LIMBIN for bovine chondrodysplastic dwarfism (bcd) that is later identified as the bovine ortholog of EVC2. Here, we report generation of conventional and conditional mutant Evc2/Limbin alleles that mimics mutations found in EvC patients and bcd cattle. Resulted homozygous mice showed no ciliary localization of EVC2 and EVC and displayed reduced Hedgehog signaling activity in association with skeletal and oral defects similar to the EvC patients. Cartilage-specific disruption of Evc2/Limbin resulted in similar but milder skeletal defects, whereas osteoblast-specific disruption did not cause overt changes in skeletal system. Neural crest-specific disruption of Evc2/Limbin resulted in defective incisor growth similar to that seen in conventional knockouts; however, differentiation of amelobolasts was relatively normal in the conditional knockouts. These results showcased functions of EVC2/LIMBIN during formation of mineralized tissues. Availability of the conditional allele for this gene should facilitate further detailed analyses of the role of EVC2/LIMBIN in pathogenesis of EvC syndrome. genesis 53:612-626, 2015. © 2015 Wiley Periodicals, Inc.

Dentomaxillofacial characteristics of ectodermal dysplasia

The aim of this retrospective hospital-based study was to elucidate the dentomaxillofacial characteristics of ectodermal dysplasia. Six Japanese individuals (one male and five female; age range, 12.7-27.2 years) underwent comprehensive examinations, including history recording, cephalometric analysis, panoramic radiography, and analysis of dental models. All the subjects had two or more major manifestations for clinical diagnosis of ectodermal dysplasia (e.g., defects of hair, teeth, nails, and sweat glands). They presented hypodontia (mean number of missing teeth, 9.5; range, 5-14), especially in the premolar region, and enamel dysplasia. Five subjects had bilateral molar occlusion, whereas one subject had unilateral molar occlusion. The common skeletal features were small facial height, maxillary hypoplasia, counterclockwise rotation of the mandible, and mandibular protrusion. Interestingly, the maxillary first molars were located in higher positions and the upper anterior facial height was smaller than the Japanese norm. The results suggest that vertical and anteroposterior maxillary growth retardation, rather than lack of occlusal support due to hypodontia, leads to reduced anterior facial height in individuals with ectodermal dysplasia.

Clinical Variability in a Family with an Ectodermal Dysplasia Syndrome and a Nonsense Mutation in the TP63 Gene

Mutations in the TP63 gene have been associated with a variety of ectodermal dysplasia syndromes, among which the clinically overlapping Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) and the Rapp-Hodgkin syndromes. We report a multiplex nonconsanguineous family of Ashkenazi-Jewish descent, in which the index patient presented with a persistent scalp skin lesion, dystrophic nails and light thin hair. Further evaluation revealed over 10 affected individuals in the kindred, over four generations, exhibiting varying degrees of ectodermal involvement. Analysis of the TP63 gene from four of the patients and from two healthy individuals of the same family was performed. Gene sequencing of the patients revealed a nonsense mutation leading to a premature termination codon (PTC) (p.Gln16X). The same mutation was found in all tested affected individuals in the family, but gave rise to marked phenotypic variability with minor clinical manifestations in some individuals, underscoring the clinical heterogeneity associated with the recently described PTC-causing mutations.

Conventional Complete Denture in Patients with Ectodermal Dysplasia

Ectodermal dysplasia is described as heritable conditions that involve anomalies of structures derived from the ectoderm, including hypodontia. In the cases of edentulous young patients, who did not finish their craniofacial growth, treatment with conventional complete denture is a suitable alternative. The aim of this study was to report a case of mandibular edentulism treated with conventional complete denture in a thirteen-year-old patient diagnosed with hidrotic ectodermal dysplasia. Typical features, such as frontal bossing, depressed nasal bridge, protuberant lips, scarce hair, and brittle nails, were visualized during the extraoral examination. The intraoral inspection and radiographic analysis revealed oligodontia, dental malformation, and prolonged retention of deciduous teeth at maxilla and total edentulism at mandible. A conventional complete denture was planned and constructed following the same steps of technique as recommended in adults. Although this option is not a definitive treatment, the patient and his parents were satisfied with his improvement in chewing and speech, as well as with the aesthetic benefits.

Second International Conference on a classification of ectodermal dysplasias: development of a multiaxis model

Ectodermal dysplasias (EDs) comprise a large clinically and etiologically heterogeneous group of genetic disorders characterized by abnormalities in tissues derived from the embryonic ectoderm. Controversy exists over which syndromes should be classified as EDs and which should be excluded from the classification. The challenge will be to balance comprehensiveness within the classification with usability and accessibility so that the benefits truly serve the needs of researchers, health-care providers, and ultimately the individuals and families directly affected by EDs. The overarching goal of the Second International Conference was to develop a consensus on EDs classifications, with the ultimate goal of creating a system that integrates clinical and molecular knowledge, using an interactive Internet-based database that clinicians, researchers, and laymen can use. The Conference, brought together a group of experts from around the world, including a diverse health-care providers, researchers, patient advocate representatives, and administrators. The Conference was modeled after the 2008 conference, with plenary sessions, scientific updates, and small group discussions. Based on the present clinical knowledge, new molecular advances and both coupled with new bioinformatics developments, the participants agree to develop a multi-axis system approach for the classification of EDs. The multi-axis approach will include a clinical/phenotype axis, a gene-based axis, and a functional/pathways axis. The significance of the conference outcomes includes, a new classification approach that will foster a better understanding of EDs, open new fields of research and develop a nosologic approach that may have broad implications for classifying other hereditary conditions.

Ear nose throat manifestations in hypoidrotic ectodermal dysplasia

The ectodermal dysplasias (EDs) are a large and complex group of inherited disorders. In various combinations, they all share anomalies in ectodermal derived structures: hair, teeth, nails and sweat gland function. Clinical overlap is present among EDs. Few causative genes have been identified, to date. Altered gene expression is not limited to the ectoderm but a concomitant effect on developing mesenchymal structures, with modification of ectodermal-mesenchymal signaling, takes place. The two major categories of ED include the hidrotic and hypohidrotic form, the latter more frequent; they differentiate each other for the presence or absence of sweat glands. We report Ear Nose Throat manifestations of ED, linked to the reduction of mucous glands in the nasal fossae with reduced ciliar function, and decrease salivary glands function. Often patients report an increased rate of infections of the upper respiratory tract and of the ear. Nasal obstruction due to the presence of nasal crusting, hearing loss and throat hoarseness are the most represented symptoms. Environmental measures, including a correct air temperature and humidification, is mandatory above all in subjects affected by hypohidrotic form.

Hypohidrotic ectodermal dysplasia: a multidisciplinary approach

Hypohidrotic ectodermal dysplasia (HED; Christ-Siemens-Touraine syndrome) is a genetic disorder characterized by sparse hair, oligodontia with peg-shaped teeth, reduced sweating, and defects in a number of other ectodermal organs. A partial or complete absence of eccrine glands can lead to recurrent severe overheating that may cause seizures and neurological deficits. This clinical report presents a 14-year-old male patient with hypohidrotic ectodermal dysplasia, including the clinical and radiographic findings, and multidisciplinary treatment. The Schedule for Affective Disorders and Schizophrenia for School Aged Children-Present and Lifetime Version (K-SADS-PL) was administered to patient along with mother to assess for any psychiatric disorders. The screening and rating scales completed by mother and two teachers to evaluate the severity of attention deficit hyperactivity disorder (ADHD) symptoms, and other behavioral problems. Patient's academic performance, adaptive functioning, and problem behavior was evaluated using. The Teacher Report Form. Mental capacity was assessed with the Wechsler Intelligence Scale for Children (WISC-R). Illness Perception Questionnaire Revised was used to systematically assess illness representation attributes and emotional representations of illness. On the psychiatric diagnosis assessment using K-SADS-PL sub-threshold attention deficits and anxiety symptoms were determined. In this case we established a multidisciplinary approach in his treatment with pediatric, dermatological, and dental examinations, beside his psychiatric evaluation. The prosthetic rehabilitation included restoring upper teeth with copings and fabrication of upper and lower complete dentures. Metal framework was not incorporated in the partial denture design allowing modifications as the oral and maxillofacial development continued. Removable complete or partial dentures without metal framework is a treatment of choice until the completion of facial growth at which definitive treatment is considered.

Clinical and histological characterization of hair coat and glandular tissue of Chinese crested dogs

BACKGROUND

Two varieties exist in the Chinese crested dog breed, namely hairless Chinese crested dogs presenting with hypotrichosis and dentition abnormalities, and the coated powderpuffs. Hairless Chinese crested dogs are obligate heterozygotes for a FOXI3 mutation, and this phenotype is classified as a form of canine ectodermal dysplasia.

OBJECTIVES

We provide a detailed histological description of hair follicles and their density for the three subphenotypes (true hairless, semi-coated and powderpuffs) of Chinese crested dogs. Apocrine and exocrine glands of the skin and other tissues were compared with findings reported from dogs with X-linked ectodermal dysplasia.

ANIMALS

Skin biopsies were collected from 22 Chinese crested dogs. Additionally, the glands of the skin and other tissues were examined from another two dogs available for postmortem examination.

METHODS

Skin biopsies and tissues were processed, stained and evaluated in a blinded fashion.

RESULTS

Hair follicular anomalies decreased with increasing number of hairs in the different phenotypes. The FOXI3 mutants had only simple primary hair follicles, whereas the nonmutant powderpuffs had compound follicles identical to other dog breeds. All Chinese crested dogs had an anagen-dominated hair cycle. Furthermore, apocrine glands in the skin and respiratory mucous glands of the mutant Chinese crested dogs were present and normal.

CONCLUSIONS AND CLINICAL IMPORTANCE

We have identified striking histopathological differences between the three subphenotypes of Chinese crested dogs. We clearly demonstrated distinct differences between the canine ectodermal dysplasia in Chinese crested dogs and dogs with X-linked ectodermal dysplasia.

Effect of complete dentures on craniofacial growth of an ectodermal dysplasia patient: a clinical report

The aim of this clinical report was to observe the effect of complete dentures on craniofacial growth and development of an ectodermal dysplasia (ED) patient. A complete anodontia patient diagnosed with ED was successfully rehabilitated with conventional complete dentures at the ages of 5, 8, and 10 years. Three sets of complete dentures were made with age-appropriate denture teeth and a bilaterally balanced lingualized occlusal scheme. Periodic follow-up and adjustment when needed was done to maintain proper oral function and esthetics. Serial cephalometric analysis exhibited a marked restriction of forward growth at the anterior nasal spine (ANS) point between 5 and 10 years of age, although there was little change from average in the anteroposterior length of the mandibular body and the height of the mandibular ramus. So, while maxillary growth was reduced, mandibular growth did not significantly change. Cast analysis showed that the increase in arch length was greater than in arch width for both the maxilla and mandible. There was little increase in alveolar ridge height in the anterior region but a considerable increase in the height of the alveolar ridge in the middle and the posterior region. Our findings concluded that the absence of teeth did not affect the growth of the jaws, and it is probable that the denture flange did not arrest the jaw growth, but rather improved the masticatory function by providing good denture stability and retention.

Ectodermal dysplasias: a clinical and molecular review

The ectodermal dysplasias are a large group of hereditary disorders characterized by alterations of structures of ectodermal origin. Although some syndromes can have specific features, many of them share common clinical characteristics. Two main groups of ectodermal dysplasias can be distinguished. One group is characterized by aplasia or hypoplasia of ectodermal tissues, which fail to develop and differentiate because of a lack of reciprocal signaling between ectoderm and mesoderm, the other has palmoplantar keratoderma as its most striking feature, with additional manifestations when other highly specialized epithelia are also involved. In recent decades, the genes responsible for at least 30 different types of ectodermal dysplasia have been identified, throwing light on the pathogenic mechanisms involved and their correlation with clinical findings.

Oral rehabilitation of children with ectodermal dysplasia

The aim of this study was to describe the clinical treatment of young patients, affected by ectodermal dysplasia (ED), and to possibly establish clinical guidelines. The study design was case series. ED syndromes (EDs) are a heterogeneous group of inherited diseases characterised by abnormal development of tissues of ectodermal origin. The most common form of EDs is X linked hypohidrotic ED (HED). Characteristic triad of HED is oligo-anodontia, hypotricosis, hypo-anhydrosis. Oligo-anodontia is one of the most severe impairment, since it affects chewing, swallowing, speech, esthetics and social relation. Early prosthetic rehabilitation (at 2-3 years of age), with partial or complete dentures, is essential to improve oral function and reduce the social impairment.