Prenatal Treatment of X-Linked Hypohidrotic Ectodermal Dysplasia using Recombinant Ectodysplasin in a Canine Model.

X-linked hypohidrotic ectodermal dysplasia (XLHED) is caused by defects in the EDA gene that inactivate the function of ectodysplasin A1 (EDA1). This leads to abnormal development of eccrine glands, hair follicles, and teeth, and to frequent respiratory infections. Previous studies in the naturally occurring dog model demonstrated partial prevention of the XLHED phenotype by postnatal administration of recombinant EDA1. The results suggested that a single or two temporally spaced injections of EDI200 prenatally might improve the clinical outcome in the dog model. Fetuses received ultrasound-guided EDI200 intra-amniotically at gestational days 32 and 45, or 45 or 55 alone (of a 65-day pregnancy). Growth rates, lacrimation, hair growth, meibomian glands, sweating, dentition, and mucociliary clearance were compared in treated and untreated XLHED-affected dogs, and in heterozygous and wild-type control dogs. Improved phenotypic outcomes were noted in the earlier and more frequently treated animals. All animals treated prenatally showed positive responses compared with untreated dogs with XLHED, most notably in the transfer of moisture through paw pads, suggesting improved onset of sweating ability and restored meibomian gland development. These results exemplify the feasibility of ultrasound-guided intra-amniotic injections for the treatment of developmental disorders, with improved formation of specific EDA1-dependent structures in dogs with XLHED.

Conservation analysis and pathogenicity prediction of mutant genes of ectodysplasin a.

BACKGROUND: Hypohidrotic ectodermal dysplasia (HED) is a common recessive X-linked hereditary disease that affects the development of ectoderm. Gene mutations of ectodysplasin A (EDA) play key roles in process of this disease. In our preliminary study, three unknown mutation sites (c.878 T > G, c.663-697del and c.587-615del) were detected from the pedigrees of HED. METHODS: Conservation analysis of the related homologous proteins in 3 unknown EDA gene mutation sites was conducted using the University of California Santa Cruz (UCSC) Genome Browser database. SIFT and PolyPhen-2, the online gene function prediction software, were utilized to predict the pathogenicity of point mutation of c.878 T > G. RESULTS: All three unknown mutation sites were located in the highly-conserved region of EDA and possessed strong amino acid conservation among different species. In addition, the results of the pathogenicity prediction of point mutation of c.878 T > G by SIFT (P = 0.00) and PolyPhen-2 (S = 0.997) demonstrated that the mutation site had considerable pathogenicity theoretically. CONCLUSIONS: The EDA mutations of c.878 T > G, c.663-697del and c.587-615del may be responsible for the pathogenesis of HED in their pedigrees.

Múltiples malformaciones vasculares en un paciente con enanismo primordial osteodisplásico microcefálico tipo II / Multiple vascular malformations in a patient with microcephalic osteodysplastic primordial dwarfism type II

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Elliptical Fourier descriptors for contours in three dimensions: a new tool for morphometrical analysis in biology.

Elliptical Fourier descriptor analysis is a method for the morphometric study of curves. It has been used in the two-dimensional plane for closed contours, but rarely for lines in the three-dimensional space. The method consists of an expansion of a contour as a sum of ellipses. In this article, we study three-dimensional contours, i.e. lines embedded in the three-dimensional space. We compute for the first time the relations between the Fourier coefficients and its geometric parameters. We then use these relations for normalization and reorientation of three-dimensional contours. Such an algorithm can be used to perform inter-individual comparisons between contours, regardless of differences in viewpoint or global size. Human and small animal illustrative examples using biomedical X-ray CT imaging data of open bone structures demonstrate the interest and potential of the method for morphological analysis.

A rat model of hypohidrotic ectodermal dysplasia carries a missense mutation in the Edaradd gene.

BACKGROUND: Hypohidrotic ectodermal dysplasia (HED) is a congenital disorder characterized by sparse hair, oligodontia, and inability to sweat. It is caused by mutations in any of three Eda pathway genes: ectodysplasin (Eda), Eda receptor (Edar), and Edar-associated death domain (Edaradd), which encode ligand, receptor, and intracellular adaptor molecule, respectively. The Eda signaling pathway activates NF-κB, which is central to ectodermal differentiation. Although the causative genes and the molecular pathway affecting HED have been identified, no curative treatment for HED has been established. Previously, we found a rat spontaneous mutation that caused defects in hair follicles and named it sparse-and-wavy (swh). Here, we have established the swh rat as the first rat model of HED and successfully identified the swh mutation. RESULTS: The swh/swh rat showed sparse hair, abnormal morphology of teeth, and absence of sweat glands. The ectoderm-derived glands, meibomian, preputial, and tongue glands, were absent. We mapped the swh mutation to the most telomeric part of rat Chr 7 and found a Pro153Ser missense mutation in the Edaradd gene. This mutation was located in the death domain of EDARADD, which is crucial for signal transduction and resulted in failure to activate NF-κB. CONCLUSIONS: These findings suggest that swh is a loss-of-function mutation in the rat Edaradd and indicate that the swh/swh rat would be an excellent animal model of HED that could be used to investigate the pathological basis of the disease and the development of new therapies.

X-linked and autosomal recessive Hypohidrotic Ectodermal Dysplasia: genotypic-dental phenotypic findings.

Hypohidrotic ectodermal dysplasia (HED) is characterized by abnormal development of ectodermal structures and its molecular etiology corresponds to mutations of EDA-EDAR genes. The aim of this study was first to investigate the genotype and dental phenotype associated with HED and second, to explore possible correlations between dental features and molecular defects. A total of 27 patients from 24 unrelated families exhibiting clinical signs of HED (22 XLHED males, 5 autosomal recessive forms) were retrospectively included. In the sample, 25 different mutations on EDA and EDAR genes were detected; 10 were not previously described. EDA and EDAR mutations corresponded respectively to 80.0% and 20.0% of the mutations. The dental phenotype analysis revealed a mean number of primary and permanent missing teeth ranging respectively from 14.5 (4-20) to 22.5 (10-28); the majority of the patients exhibited dysmorphic teeth. Overall, no differential expression in the degree of oligodontia according to either the mutated gene, the mutated functional sub-domains, or the mutation type, could be observed. Nevertheless, the furin group exhibited severe phenotypes unobserved in the TNF group. Significant differences in the number of some primary missing teeth (incisor and canine) related to EDA-EDAR genes defects were detected for the first time between XLHED and autosomal recessive HED, suggesting differential local effects of EDA-EDAR genes during odontogenesis. The present genotypic-phenotypic findings may add to the knowledge of the consequences of the molecular dysfunction of EDA-NF-kB in odontogenesis, and could be helpful in genetic counseling to distinguish autosomal forms from other HED syndromes.

A novel splice site mutation in the EDAR gene underlies autosomal recessive hypohidrotic ectodermal dysplasia in a Pakistani family.

Hypohidrotic ectodermal dysplasia is a rare congenital disorder that results in abnormalities in the structures of ectodermal origin: hair, teeth, and eccrine sweat glands. DNA sequence analysis of EDAR gene in a Pakistani family, demonstrating autosomal recessive form of hypohidrotic ectodermal dysplasia, identified a novel homozygous mutation affecting splice donor site of exon 5 [IVS5+1G > or = C] of the gene.

Hypohidrotic ectodermal dysplasia.

We report three children with hypohidrotic ectodermal dysplasia (HED), which includes two sisters with unaffected parents (and therefore likely autosomal recessive inheritance of HED) and an unrelated boy. Each patient presented with hypohidrosis, sparse hair, oligodontia with conical teeth, periorbital hyperpigmentation, eczematous dermatitis, and facial features that include frontal bossing, a saddle nose, and prominent lips. HED is caused by defects in the ectodysplasin signal transduction pathway. Mutations in the gene encoding the ligand ectodysplasin A (EDA) underlie classic, X-linked recessive HED, whereas mutations in the genes encoding the EDA receptor and (less frequently) the adaptor protein that associates with the EDA receptor's death domain result in autosomal dominant and autosomal recessive forms of HED.

Unusual presentation of a severe autosomal recessive anhydrotic ectodermal dysplasia with a novel mutation in the EDAR gene.

We report on an 18-year-old woman, born to first-cousin parents, presenting with a severe form of anhydrotic ectodermal dysplasia (EDA/HED). She had sparse hair, absent limb hair, absent sweating, episodes of hyperpyrexia, important hypodontia, and hyperconvex nails. She also showed unusual clinical manifestations such as an absence of breasts, a rudimentary extranumerary areola and nipple on the left side, and marked palmo-plantar hyperkeratosis. Light microscopy of skin biopsies showed orthokeratotic hyperkeratosis and absence of sweat glands. A novel homozygous mutation (IVS9 + 1G > A) in the EDAR gene was identified. This mutation results in a total absence of EDAR transcripts and consequently of the EDAR protein, which likely results in abolition of all ectodysplasin-mediated NF-kappaB signaling. This is the first complete loss-of-function mutation in the EDAR gene reported to date, which may explain the unusual presentation of HED in this patient, enlarging the clinical spectrum linked to the dysfunction of the ectodysplasin mediated NF-kappaB signaling.

Craniofacial and upper airway cephalometrics in hypohidrotic ectodermal dysplasia.

OBJECTIVES: The aim of this study was to evaluate the craniofacial and upper airway structures in patients with hypohidrotic ectodermal dysplasia (HED). SUBJECTS AND METHODS: Craniofacial and upper airway dimensions were measured on lateral cephalometric radiographs of ten HED patients (four females and six males) and ten normal class III patients as a control group. 21 dimensional measurements were used for cephalometric assessment. Craniofacial structures were compared with normal values and airway dimensions were compared with those of a control group with a similar skeletal pattern. RESULTS: We found that the SNA degrees, SNB degrees, ANB degrees, SN-GoMe degrees and the distance between the lips and the S-line were lower than those in normal subjects, while soft tissue convexity angles were higher in HED patients. Statistically significant decreases occurred in tongue length, vertical airway length, hyoid bone mandibular plane length, hyoid bone C3 length, middle airway space and inferior airway space, while the soft palate length increased. CONCLUSIONS: The characteristic craniofacial features of HED patients are class III malocclusion with maxillary retrusion and deficiency in vertical, transversal and sagittal growth of the jaw and soft tissues. HED patients have smaller pharyngeal and upper airway dimensions, and the hyoid bone is positioned more posteriorly compared with class III control individuals.