Prenatal Correction of X-Linked Hypohidrotic Ectodermal Dysplasia.

Genetic deficiency of ectodysplasin A (EDA) causes X-linked hypohidrotic ectodermal dysplasia (XLHED), in which the development of sweat glands is irreversibly impaired, an condition that can lead to life-threatening hyperthermia. We observed normal development of mouse fetuses with Eda mutations after they had been exposed in utero to a recombinant protein that includes the receptor-binding domain of EDA. We administered this protein intraamniotically to two affected human twins at gestational weeks 26 and 31 and to a single affected human fetus at gestational week 26; the infants, born in week 33 (twins) and week 39 (singleton), were able to sweat normally, and XLHED-related illness had not developed by 14 to 22 months of age. (Funded by Edimer Pharmaceuticals and others.).

Sweating ability of patients with p63-associated syndromes.

Sweating deficiency has been reported to represent a cardinal symptom of ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome and ankyloblepharon-ectodermal dysplasia-cleft lip/palate syndrome, two rare p63-associated disorders. According to online resources, hypohidrosis may lead to most life-threatening complications in affected patients. Thus, counseling on the prevention of hyperthermia would be indispensable in case of such syndromes, although detailed information on this issue is missing in the literature. We investigated 14 individuals with ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome (age range 2-48 years) and 9 individuals with ankyloblepharon-ectodermal dysplasia-cleft lip/palate syndrome (0.5-60 years of age) by confocal laser scanning microscopy to determine their palmar sweat duct density and by quantification of pilocarpine-induced sweating. Genotype-phenotype correlations were assessed. In 12 of 23 patients (52%), a normal amount of sweat ducts was detected. These individuals (9 with ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome, 3 with ankyloblepharon-ectodermal dysplasia-cleft lip/palate syndrome) produced sufficient sweat volumes (≥ 20 µl) in response to pilocarpine. All other patients had clearly reduced sweating ability and fewer sweat glands, but no anhidrosis. Alteration of a specific proline residue (Pro590) of p63 was consistently linked to impaired perspiration.Conclusion: Hypohidrosis in p63-associated syndromes is less common and potentially less severe than previously thought and may be attributable to certain genotypes. What is Known: • Hypohidrosis which has been listed as a cardinal symptom of AEC and EEC syndromes may lead to life-threatening hyperthermia. What is New: • Patients with EEC and AEC syndromes often can sweat normally. • Hypohidrosis seems to be attributed to certain TP63 genotypes.

Atopic diathesis in hypohidrotic/anhidrotic ectodermal dysplasia.

Recently, patients with hypohidrotic/anhidrotic ectodermal dysplasia (H/AED) have been reported to have a higher prevalence of symptoms suggestive of atopic disorders than the general population. To better understand atopic diathesis in H/AED, 6 cases of clinically or genetically diagnosed H/AED were examined. The following criteria were evaluated with patient consent: sweating, blood test results, histopathology and filaggrin staining. Five of 6 H/AED cases displayed atopic dermatitis-like manifestations, and 3 of these 5 cases experienced periorbital lesions. H/AED patients tended to present with atopic dermatitis-like eruptions with characteristics potentially indicative of periorbital lesions. Atopic diathesis in H/AED appeared not to be associated with filaggrin. We could speculate that hypohidrosis or anhidrosis itself might impair skin barrier function and contribute to atopic diathesis.

Dermatoscopy as an adjunctive diagnostic tool in aquagenic syringeal acrokeratoderma.

Aquagenic syringeal acrokeratoderma (ASA) is a rare skin disorder of the palms and/or soles, characterized by whitish papules with occasional pruritus or pain sensation. Herein we report a 27-year-old man with a diagnosis of ASA based on clinical and histopathological features, and describe the dermatoscopic features consistent with threefold enlarged sweat duct pores compared with a normal-looking palmar skin area. As far as we are aware, dermatoscopic features of ASA have not been reported so far.

Sweating ability and genotype in individuals with X-linked hypohidrotic ectodermal dysplasia.

BACKGROUND: X-linked hypohidrotic ectodermal dysplasia (XLHED), the most common type of ectodermal dysplasia, is caused by EDA gene mutations. Reduced sweating contributes substantially to XLHED associated morbidity and mortality. To characterise the genotype-phenotype relationship, sweat gland function was assessed non-invasively in XLHED patients and healthy controls. SUBJECTS AND METHODS: In 36 genotyped XLHED patients and 29 control subjects aged 0-57 years, pilocarpine-induced sweat volume, palmar sweat pore density, and palmar skin conductance before and after stimulation were determined. RESULTS: Among 31 XLHED males, 14 had neither detectable sweat pores nor inducible sweating, 10 showed a few sweat pores but absent sweating, and 7 produced reduced sweat volumes (1-11 µl) as compared with controls (38-93 µl). Two of the low sweating XLHED subjects had normal sweat pore counts. In all 5 heterozygous females, some sweat was detected, but generally less than in female controls. Basal and stimulated skin conductance readings were reduced in 23 of 24 non-sweating, but only in 3 of 12 low-sweating XLHED subjects. There was no correlation between sweat production and number of missing teeth. CONCLUSIONS: In contrast to prior reports on non-genotyped hypohidrotic ectodermal dysplasia populations, this study confirmed a consistent, quantifiable defect of sweat gland function in male XLHED subjects as a disease biomarker. Among 26 different EDA genotypes, specific mutations were shown to be consistently associated with anhidrosis, implying that systematic mapping of EDA mutations together with the analysis of objective clinical data may help to distinguish functionally crucial mutations from those allowing residual activity of the gene product.

Hypohidrotic (anhidrotic) ectodermal dysplasia in female twins.

Autosomal recessive hereditary ectodermal dysplasia (HED) has not been described in sub-Saharan Africa. It is acknowledged to be rarer than the occasionally reported x-linked and autosomal dominant variants. We report a pair of Nigerian female twins with family history and clinical features suggestive of recessive HED, thereby showing the existence of this rare form in sub-Saharan Africa.

Two patients with localised hyperhidrosis of the hand based on functional and structural abnormalities of sweat glands.

A 14-year-old girl and a 30-year-old woman presented with localised hyperhidrosis on the dorsal hand and wrist, respectively, provoked by different stimuli such as physical activity and minor trauma to the skin. The skin was seemingly normal in both patients where an iodine-starch test revealed a well-demarcated area of hyperhidrosis. Following histopathological examination, the diagnosis was unilateral localised hyperhidrosis in both cases; one with normal histology and one with a nevus sudoriferous. Both patients were successfully treated with botulinum toxin type A. The 30-year-old woman additionally used low-dose propantheline bromide periodically and experienced long-term remission on this therapy. Hyperhidrosis may embarrass and interfere with patients' school and careers, and it is therefore important to tailor an effective individual treatment.

Global developmental delay, osteopenia and ectodermal defect: a new syndrome.

UNLABELLED: Global developmental delay is a serious social problem. It is often unrecognized and the phenotypes are inadequately studied. To investigate the phenotypes of children with aspecific central nervous system (CNS) impairment (poor speech, maladaptive behavioral symptoms such as temper tantrums, aggressiveness, poor concentration and attention, impulsiveness, and mental retardation). SETTING: Tertiary care hospital. PATIENTS: Three children (two male siblings, and one unrelated girl). METHODS: We used the results from clinical neurological evaluations; imaging and electrodiagnostic studies; metabolic and genetic tests; skin biopsies and bone mineral densitometry. All three children suffered from (A) global developmental delay, (B) osteopenia, and (C) identical skin defects. The skin ultrastructural abnormalities were abnormal keratin differentiation, consisting of hyperkeratosis and granular layer thickening; sweat gland abnormalities, consisting of focal, cytoplasmic clear changes in eccrine secretory cells; and melanocyte abnormalities, with both morphological changes (reduced number and size without evident dendritic processes), and functional changes (defects in the migration of melanosomes in the keratinocytes). These patients present a previously unrecognized syndrome. We retain useful to report this new association, to be recognized, in the next future, as a specific key-sign of a well-defined genetic defect.

Anhidrosis and absence of sweat glands in mice hemizygous for the Tabby gene: supportive evidence for the hypothesis of homology between Tabby and human anhidrotic (hypohidrotic) ectodermal dysplasia (Christ-Siemens-Touraine syndrome).

I have suggested that the X-linked gene Tabby (Ta) and its autosomal mimics in the mouse may be homologous with the genes for sex-linked anhidrotic (hypohidrotic) ectodermal dysplasia (Christ-Siemens-Touraine syndrome, CST) and its apparent autosomal mimics in the human. In the present study, I examined whether anhidrosis, a cardinal feature of CST, is present in the putative mouse sex-linked model, Tabby. The results demonstrate that whereas normal mice perspire on the volar and plantar surfaces of their paws, hemizygous Ta/Y male mice show anhidrosis and absence of sweat glands, as do human hemizygous male sufferers of CST. This result is strongly supportive of the hypothesis that Ta is homologous to the gene for CST.

Innervation of footpads of normal and mutant mice lacking sweat glands.

Footpads of normal adult mice are innervated by sympathetic and sensory fibers. The sympathetic fibers associated with sweat glands contain acetylcholinesterase and immunoreactivity for vasoactive intestinal peptide. Although catecholamine histofluorescence is absent, the gland innervation exhibits immunoreactivity for tyrosine hydroxylase. A distinct population of sympathetic fibers, which possess catecholamines and neuropeptide Y as well as tyrosinehydroxylase immunoreactivity, innervates blood vessels. Sensory fibers containing immunoreactivity for substance P and calcitonin gene-related peptide course beneath the epidermis and some form endings in it. Treatment of neonatal mice with the adrenergic neurotoxin, 6-hydroxydopamine, results in loss of sympathetic innervation of sweat glands and blood vessels, permits growth of sensory axons into sweat glands, but does not alter the peptidergic sensory innervation of the dermis and epidermis. Three mouse mutations, Tabby (Ta), crinkled (cr), and downless (dl), disrupt the interactions between the mesenchyme and epidermis that are required for normal development of specific epidermal derivatives, including sweat glands. The sympathetic innervation of blood vessels and sensory innervation of footpad skin of the three mutant mice that lack sweat glands is indistinguishable from normal. The sympathetic fibers that normally innervate sweat glands, however, are not present. These results indicate that in the absence of their normal target, the sympathetic fibers that innervate sweat glands are lacking. Furthermore, they suggest that, although sensory fibers may sprout into sympathetic targets in the footpad, the domains occupied by sensory fibers are not normally accessible to sympathetic axons.

Familial simple hypohidrosis with abnormal palmar dermal ridges.

A brother and sister born to nonconsanguineous, Iranian Jewish parents were found to have simple hypohidrosis. Pilocarpine produced only little sweating, and external heat and physical effort were associated with elevation of body temperature. Abnormal palmar dermal ridges were considered to be associated with paucity of sweat pores and glands. Biopsy supported this view since only one normal sweat gland and duct was found in a 5 mm punch.

[Ectodermal anhidrotic dysplasia (author's transl)]. / Dysplasie ectodermique anhidrotique.

The E. A. D. is a genodermatosis characterised by absence or important diminuation of sweat glands. The study of 3 children of different families allows us to identify the diagnostic elements: typical facial signs, anhidrosis, rarity of teeth "buds", abnormalities of dermatoglyphes. This diagnosis must be established early, to protect the newborn from accidents of overheating caused by perspiration insufficiency. The sweat glands are not affected alone: exocrine glands also, explaining the fragility of the upper respiratory tract in such patients. The teeth abnormalities are important and need replacement by false teeth, carefully done at an early date and continued later on. Genetic investigation is indispensable to discover women who carry the disease, with a high risk of transmission to their children.