Alternative titles; symbols. Some ectodermal dysplasias are here classified as congenital disorders characterized by abnormal development in 2 or more ectodermal structures hair, nails, teeth, and sweat glands without other systemic findings. Typical clinical manifestations also include dryness of the skin, eyes, airways, and mucous membranes presumably due to the defective development of several exocrine glands. Hypohidrotic ectodermal dysplasia can be associated with dysmorphic features forehead bumps, rings under the eyes, everted nose, and prominent lips and occasionally with absent nipples. Ectodermal dysplasia-1, due to mutation in the EDA gene, is the most frequent form of hypohidrotic ectodermal dysplasia summary by Cluzeau et al. Pinheiro and Freire-Maia reported a large Brazilian kindred with multiple affected individuals over 6 generations.
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Alternative titles; symbols. Some ectodermal dysplasias are here classified as congenital disorders characterized by abnormal development in 2 or more ectodermal structures hair, nails, teeth, and sweat glands without other systemic findings.
Typical clinical manifestations also include dryness of the skin, eyes, airways, and mucous membranes presumably due to the defective development of several exocrine glands. Hypohidrotic ectodermal dysplasia can be associated with dysmorphic features forehead bumps, rings under the eyes, everted nose, and prominent lips and occasionally with absent nipples.
Ectodermal dysplasia-1, due to mutation in the EDA gene, is the most frequent form of hypohidrotic ectodermal dysplasia summary by Cluzeau et al. Pinheiro and Freire-Maia reported a large Brazilian kindred with multiple affected individuals over 6 generations. Thirteen males were affected and 27 females were variably affected. Males had a characteristic facies, with frontal bossing, maxillary hypoplasia, 'saddle' nose, prominent lips, and linear wrinkles around the eyes.
Teeth were often missing or misshapen. Hair was fine, dry, brittle, and sparse, and skin was thin, glossy, smooth, and dry with hypohidrosis. Females had sparse, thin scalp hair and mosaic patchy distribution of body hair. Many females had abnormal teeth and mild hypohidrosis.
Pinheiro and Freire-Maia suggested that the syndrome had 2 forms: a 'major' form in males, and a 'minor' form in females. Pinheiro et al. Nakata et al. All affected males had the characteristic clinical findings of HED, including very sparse hair, small, misshapen, and missing teeth, diminished sweating with a history of frequent hospitalization for high fevers during infancy, and symptoms of atrophic rhinitis and decreased salivary secretions.
All affected males had normal nails. Seven other male family members were reported to be affected, including 6 who died before 1 year of age with high fevers. Two affected males had total anodontia, several had missing teeth bilaterally, and most had significantly smaller upper incisors, upper and lower first molars, and lower second molars than controls. Seventy-three percent of obligate heterozygous females had 1 or more congenitally missing teeth, and most had smaller teeth, One daughter had severe thinning of the hair and several mothers were known to wear wigs.
The findings suggested that HED is a highly penetrant X-linked trait with intermediate expression in the heterozygous female. Autopsy in 1 patient Reed et al. The finding was thought to be the basis for the observed increase in susceptibility to respiratory infections. Mucous glands were also absent in the upper esophagus and hypoplastic in the colon. In 13 HED families with 16 affected males, Saksena and Bixler described detailed facial characteristics, including prominent forehead, narrow and short maxillary regions, small palatal depth, small cranial length, and depressed nasal root and bridge.
Heterozygous carriers showed variable manifestations of these facial characteristics. Crawford et al. Abinun et al. Halperin and Curtis reported an association with mental retardation, but this is usually not a feature of the syndrome.
In the family reported by Roberts , skin involvement in heterozygous females was patchy. Singh et al. Two brothers had died of the disease. Whether this was a homozygous affected or a heterozygous manifesting female is uncertain, especially since no information was provided on whether the father was affected. Consanguineous matings of the types that are expected to result in homozygous affected females are frequent in some Indian groups.
Richards and Kaplan described a female infant with neonatal pyrexia due to anhidrotic ectodermal dysplasia. The mother had 'somewhat sparse hair and wrinkled appearance of the eyelids. The authors suggested autosomal dominant inheritance. Earlier, Kerr et al. The family of Richards and Kaplan is consistent with X-linked inheritance with partial expression in heterozygous females.
Happle and Frosch demonstrated that heterozygotes show a pattern of lyonization that corresponds, over the back, for example, to lines of Blaschko. They reproduced one of Blaschko's original drawings Blaschko, and showed a photograph of the iodine-starch test of the back of a patient showing the same lines with a typical V-shape over the spine.
Happle presented diagrams of the lines of Blaschko with a demonstration of the findings on the scalp where spiral streaks converge on the vertex. Carrier detection is often possible by dental examination; whole-back sweat tests are useful to supplement the dental examination when necessary Harper, Clark et al.
Clarke and Burn found positive sweat tests as indicated by mosaic hypohidrosis following the lines of Blaschko in 35 of 36 obligate female carriers. Furthermore, female carriers identified in HED families on the basis of unequivocal dental signs were found to give positive results in 44 of 47 cases. The authors noted that diagnosis of females carriers is important to optimize neonatal and pediatric care for affected male infants who may be at substantial risk of death in infancy.
MacDermot and Hulten reported follow-up on the girl with the X;9 translocation and confirmed the diagnosis of hypohidrotic ectodermal dysplasia with moderately severe mental retardation. The patient had been born of a nonconsanguineous couple with maternal age 43 and paternal age During her first year, she had severe feeding problems necessitating gastrostomy and episodes of unexplained hyperpyrexia. She was noted to have fine and sparse hair but with no family history.
The diagnosis of HED was not made until she was 1 year old. Zankl et al. Like the patient studied by MacDermot and Hulten , these patients were severely affected. One of the girls died unexpectedly at 2.
Autopsy revealed complete absence of sebaceous, submucous, and eccrine sweat glands as well as severe hypoplasia of hair follicles. The left main stem bronchus was obstructed by mucous debris. Lack of normal tracheobronchial secretions leading to complete tracheal obstruction by mucous debris was considered the likely cause of death.
Lexner et al. None of 41 additional females with sparse clinical features had skewed X-chromosome inactivation. Gilgenkrantz et al. Specimens showed a complete lack of pilosebaceous units. Zonana et al. On the basis of advice, the pregnancy was terminated. The diagnosis could not be confirmed by histologic analysis because of the early developmental stage of the fetus. Chautard-Freire-Maia et al. Cook suggested that the disease gene might be located in Xq12, based on the girl with HED and the X;9 translocation.
This statement was not recorded in the workshop report, but was communicated by Dr. Cook to Albert de la Chapelle in de la Chapelle , Since the break in the X chromosome was in Xq12, the possibility that the EDA locus is situated there was raised de la Chapelle, Turleau et al.
From comparative mapping studies of the X chromosomes of mouse and man, including mapping of 'Tabby' Ta , the presumed mouse homolog of EDA, Buckle et al. MacDermot et al. Kolvraa et al. This gave a maximum lod score of 2. Clarke et al. Hanauer et al. A full review was provided by Clarke They concluded that the disorder is located in the region Xqq On the basis of studies in 24 families using 7 DNA markers from the centromeric region of the X chromosome, Kruse et al.
The absence of recombination lends support to the hypothesis that the DXCrc locus in the mouse and the DXS locus in humans contain candidate sequences for the Ta and EDA genes, respectively.
Limon et al. The breakpoint at Xq In a male patient with the classic EDA phenotype, Zonana et al. This was the first determination of carrier status for EDA in females by direct mutation analysis. Since the DXS locus contains a highly conserved sequence, Zonana et al.
Kere et al. The authors noted that mutations were detected in only one-tenth of patients studied. In 17 of 18 families with X-linked hypohidrotic ectodermal dysplasia, Monreal et al.
In 2 Han Chinese brothers with X-linked hypohidrotic ectodermal dysplasia and their unaffected mother, Huang et al. The mutation was not found in the maternal grandparents or in controls.
The authors stated that this was the first de novo insertion identified in the EDA gene. Van der Hout et al. Nine of the mutations were novel. In addition, multiplex ligation-dependent probe amplification MLPA analysis detected a deletion in exon 1. Van Steensel et al. The patient reported occasional blistering as a child, inability to sweat, although he could tolerate heat, slow-growing hair, and congenital absence of teeth, except for 2 conical teeth in the upper jaw.
He attended business school and was otherwise healthy. Physical examination revealed a massive, hystrix-like dark brown malodorous hyperkeratosis covering large skin areas, which diminished toward the extremities and was absent on the palms and soles.
Hypohidrotic Ectodermal Dysplasia
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Natural history of X-linked hypohidrotic ectodermal dysplasia: a 5-year follow-up study
Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed. Hypohidrotic ectodermal dysplasia with immunodeficiency HED-ID is a type of HED see this term characterized by the malformation of ectodermal structures such as skin, hair, teeth and sweat glands, and associated with immunodeficiency. Prevalence is not known.
Hypohidrotic ectodermal dysplasia
Hypohidrotic ectodermal dysplasia is one of more than types of ectodermal dysplasia. Starting before birth, these disorders result in the abnormal development of ectodermal tissues, particularly the skin, hair, nails, teeth, and sweat glands. Most people with hypohidrotic ectodermal dysplasia have a reduced ability to sweat hypohidrosis because they have fewer sweat glands than normal or their sweat glands do not function properly. Sweating is a major way that the body controls its temperature; as sweat evaporates from the skin, it cools the body. Reduced sweating can lead to a dangerously high body temperature hyperthermia , particularly in hot weather.