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.

Prosthetic rehabilitation of patients with hypohidrotic ectodermal dysplasia: A systematic review.

Hypohidrotic ectodermal dysplasia (HED) comprises a large group of inherited disorders of ectodermal structures, characterised by hypo- or anhidrosis, hypotrichosis and hypo- or oligo- or anodontia. We aimed to systematically assess the spectrum of prosthodontic approaches with regard to the patients' age and to provide clinical implications for practicing dentists. An electronic and manual search was conducted in four databases (Medline, LIVIVO, Cochrane Library, Web of Science Core Collection). Publications of multiple study designs written in English or German without data restrictions, reporting on prosthodontic treatment of patients diagnosed with HED and afflicted with oligo- or anodontia, were included. In total, 75 articles on 146 patients were analysed according to the patients' age. In children aged 2-17 years, removable full or partial (over)dentures represented standard treatment. In the mandible, implant-supported removable dentures on two interforaminal implants presented an alternative, already in young childhood. In cases with more than six teeth per jaw, also fixed (resin) bridges were used, frequently after orthodontic treatment. In adults, fixed or removable reconstructions with the help of up to eight implants per jaw, usually placed after bone augmentation procedures, were standard. Ten case reports/series with long-term follow-up illustrated the need for consistent maintenance including denture renewals. Prosthodontic rehabilitation should start in early childhood and needs to be revised in accordance with the patients' growth. Treatment should be carried out by a multidisciplinary team addressing variable demands in different age groups.

Automatic recognition of the XLHED phenotype from facial images.

X-linked hypohidrotic ectodermal dysplasia (XLHED) is a genetic disorder that affects ectodermal structures and presents with a characteristic facial appearance. The ability of automated facial recognition technology to detect the phenotype from images was assessed . In Phase 1 of this study we examined if the age of male patients affected the technology's recognition. In Phase 2 we investigated how well the technology discriminated affected males cases from female carriers and from individuals with other ectodermal dysplasia syndromes. The system detected XLHED to be the most likely diagnosis in all genetically confirmed affected male patients of all ages, and in 55% of heterozygous females. Interestingly, patients with other ED syndromes were also detected by the XLHED-targeted analysis, consistent with shared developmental features. Thus the automated facial recognition system represents a promising non-invasive technology to screen patients at all ages for a possible diagnosis of ectodermal dysplasia, with greatest sensitivity and specificity for males affected with XLHED.

Ectodysplasin A protein promotes corneal epithelial cell proliferation.

The EDA gene encodes ectodysplasin A (Eda), which if mutated causes X-linked hypohidrotic ectodermal dysplasia (XLHED) disease in humans. Ocular surface changes occur in XLHED patients whereas its underlying mechanism remains elusive. In this study, we found Eda was highly expressed in meibomian glands, and it was detected in human tears but not serum. Corneal epithelial integrity was defective and the thickness was reduced in the early postnatal stage of Eda mutant Tabby mice. Corneal epithelial cell proliferation decreased and the epithelial wound healing was delayed in Tabby mice, whereas it was restored by exogenous Eda. Eda exposure promoted mouse corneal epithelial wound healing during organ culture, whereas scratch wound assay showed that it did not affect human corneal epithelial cell line migration. Epidermal growth factor receptor (EGFR), phosphorylated EGFR (p-EGFR), and phosphorylated ERK1/2 (p-ERK) were down-regulated in Tabby mice corneal epithelium. Eda treatment up-regulated the expression of Ki67, EGFR, p-EGFR, and p-ERK in human corneal epithelial cells in a dose-dependent manner. In conclusion, Eda protein can be secreted from meibomian glands and promotes corneal epithelial cell proliferation through regulation of the EGFR signaling pathway. Eda release into the tears plays an essential role in the maintenance of corneal epithelial homeostasis.

Ectodysplasin signalling deficiency in mouse models of hypohidrotic ectodermal dysplasia leads to middle ear and nasal pathology.

Hypohidrotic ectodermal dysplasia (HED) results from mutation of the EDA, EDAR or EDARADD genes and is characterized by reduced or absent eccrine sweat glands, hair follicles and teeth, and defective formation of salivary, mammary and craniofacial glands. Mouse models with HED also carry Eda, Edar or Edaradd mutations and have defects that map to the same structures. Patients with HED have ear, nose and throat disease, but this has not been investigated in mice bearing comparable genetic mutations. We report that otitis media, rhinitis and nasopharyngitis occur at high frequency in Eda and Edar mutant mice and explore the pathogenic mechanisms related to glandular function, microbial and immune parameters in these lines. Nasopharynx auditory tube glands fail to develop in HED mutant mice and the functional implications include loss of lysozyme secretion, reduced mucociliary clearance and overgrowth of nasal commensal bacteria accompanied by neutrophil exudation. Heavy nasopharynx foreign body load and loss of gland protection alters the auditory tube gating function and the auditory tubes can become pathologically dilated. Accumulation of large foreign body particles in the bulla stimulates granuloma formation. Analysis of immune cell populations and myeloid cell function shows no evidence of overt immune deficiency in HED mutant mice. Our findings using HED mutant mice as a model for the human condition support the idea that ear and nose pathology in HED patients arises as a result of nasal and nasopharyngeal gland deficits, reduced mucociliary clearance and impaired auditory tube gating function underlies the pathological sequelae in the bulla.

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.

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.

Systematic evaluation of exertional hyperthermia in children and adolescents with hypohidrotic ectodermal dysplasia: an observational study.

To evaluate exertional overheating and the impact of physical exercise on individuals with hypohidrotic ectodermal dysplasia (HED) and to assess protective effects of cooling devices, 13 boys and male adolescents with X-linked HED (XLHED) and age-matched healthy male controls were studied during standardized exercise on a bicycle ergometer at ambient temperatures of 25 and 30°C, without cooling and with evaporative skin cooling devices at 30°C. Body core temperature during and after exercise, heart rate, performance, endurance, and serum lactate were investigated. XLHED subjects experienced a significantly greater rise in body temperature after cycling than healthy controls, and their body temperature remained elevated longer. Maximum heart rates and lactate values did not differ significantly between XLHED and control groups. Application of skin cooling devices led to a clinically relevant attenuation of exertional hyperthermia in XLHED patients, and a previous tendency toward lower performance disappeared. This first systematic study of the effects of physical exercise on HED patients demonstrates a rapid and lasting body temperature increase in XLHED subjects after cycling, posing them at risk of exercise-induced hyperthermia. External evaporative skin cooling attenuates exertional overheating in HED patients and may facilitate their participation in athletic activities and professional life.

Craniofacial growth in ectodermal dysplasia. An 8 year longitudinal evaluation of Italian subjects.

OBJECTIVE: To identify the main directions of growth of facial structures in subjects with hypohidrotic ectodermal dysplasia (HED). MATERIALS AND METHODS: The 3D noninvasive facial measurements were collected in 12 subjects (6 boys, 6 girls) with HED during four assessments (at 8, 11, 12, and 15 years) using an electromagnetic digitizer. The modifications of linear distances in the upper, middle, and lower third of the face were analyzed and compared with cross-sectional data obtained in normal healthy coetaneous. For each distance, differential values between the last and the initial data were calculated individually, separately for a first (8-11 years) and a second growth period (12-15 years). RESULTS: In the first time span, the growth of all facial measurements was reduced in HED subjects compared with control subjects. During this interval, most of the HED children underwent a functional and/or prosthetic treatment. During adolescence, the width and height of the lower and upper facial thirds showed a larger growth in HED subjects than in control subjects, while all facial depths and all distances in the middle facial third maintained a reduced growth. CONCLUSIONS: The deviation from normal facial growth of HED subjects tends to lessen with age. Functional and prosthetic appliances may have enhanced facial growth.

A novel 22-bp deletion mutation in a Chinese family with X-linked hypohidrotic ectodermal dysplasia.

X-linked hypohidrotic ectodermal dysplasia (XLHED) is the most common form of the ectodermal dysplasias characterized by an abnormal development of eccrine sweat glands, hair and teeth. Pathogenic mutations in the ED1 gene have been identified. In this family, a 22-bp deletion mutation of exon 8 in the ED1 gene was found in the affected members but not in the healthy individuals and 100 unrelated controls. We add new variant to the knowledge of ED1 mutations in XLHED.

Whole saliva in X-linked hypohidrotic ectodermal dysplasia.

BACKGROUND: X-linked hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia. Identification of female carriers of X-linked HED can be difficult because of varying degrees of clinical symptoms due to the X-chromosome inactivation. This is the first study about whole saliva flow and composition in males affected by HED and female carriers all confirmed by molecular genetic analysis. HYPOTHESIS AND AIM: As salivary glands derive from ectoderm, we hypothesized that whole saliva flow and composition are altered in males affected by HED and female carriers. DESIGN: Saliva flow and composition were examined in a group of affected males and in a group of female carriers, all confirmed by molecular genetic analysis, and compared with healthy male and female controls. RESULTS: Affected males and female carriers had reduced whole saliva flow and saliva with high concentrations of most inorganic salivary constituents as well as total protein. However, affected males and female carriers seemed to have reduced amylase activity and concentration relative to their total protein concentration. CONCLUSION: Saliva flow and composition may be used as part of a comprehensive clinical examination to identify potential female carriers of HED.