Displasia ectodérmica hipohidrótica ligada al cromosoma X de novo por variante recurrente en un paciente mexicano / X-linked hypohidrotic ectodermal dysplasia by a de novo recurrent variant in a Mexican patient

Resumen Introducción: Las displasias ectodérmicas son un grupo de genodermatosis que se caracterizan por distrofia de las estructuras derivadas del ectodermo. De ellas, la variedad más común es la hipohidrótica, con una incidencia de 7/100,000 nacidos vivos observada en todos los grupos étnicos. La displasia ectodérmica hipohidrótica tiene distintas etiologías. La presentación más frecuente es la asociada a un patrón de herencia ligado al cromosoma X, causada por variantes patogénicas del gen EDA en Xq13.1. EDA codifica a la ectodisplasina A, una molécula de señalización que participa en la comunicación epitelio-mesénquima durante el desarrollo de la piel y los anexos. Caso clínico: Varón de 6 años con las características clínicas cardinales de la displasia ectodérmica hipohidrótica ligada al cromosoma X (DEHLX), que incluyen hipotricosis, oligodoncia e hipohidrosis. El análisis del gen EDA por secuenciación directa mostró la presencia de la variante patogénica c.466C>T, p.Arg156Cys, rs132630313 con presentación de novo en el paciente. Esta variante ya ha sido reportada en diferentes poblaciones, incluyendo familias mexicanas, y constituye un punto caliente para mutación en EDA. Se analizaron los hallazgos clínicos, la etiología y el manejo de la DEHLX, en la que de manera reciente se ha planteado la posibilidad de otorgar tratamiento prenatal para prevenir sus manifestaciones clínicas. Conclusiones: Se pone de relevancia que el análisis molecular en pacientes con DEHLX corrobora el diagnóstico clínico y permite brindar asesoramiento genético con bases moleculares.

Abstract Background: Ectodermal dysplasias are a group of genodermatoses characterized by dystrophy of ectodermal derived structures. The most frequent presentation of the ectodermal dysplasias is the hypohidrotic type, which has an incidence of 7/100,000 newborns and has been described in all ethnic groups. The hypohidrotic ectodermal dysplasia (HED) has different etiologies, and it is more frequently associated with an X-linked pattern of inheritance caused by pathogenic variants of the EDA gene in Xq13.1. EDA encodes the protein ectodisplasin A, a signal molecule which participates in epithelium and mesenchymal development of the skin. Case report: A 6 year-old male patient with the main clinical characteristics of the X-linked HED including hypotrichosis, hypodontia and hypohidrosis. The direct sequencing analysis of EDA in our patient detected a de novo pathogenic variant, c.466C>T, p.Arg156Cys, rs132630313. This variant has been previously described in different ethnic groups, including Mexican families, and is considered a mutational hotspot. The clinical characteristics, etiology and management of the X-linked HED, including the possibility of prenatal therapy in order to avoid the clinical manifestations are discussed. Conclusions: The molecular analysis in patients with X-linked HED is of relevance, as it enables to confirm the clinical diagnosis and also, it allows a genetic assessment with molecular bases.

Estudio dínico y molecular en una familia con displasia ectodermica hipohidrotica autosomica dominante / Clinical and molecular study in a family with autosomal dominant hypohidrotic ectodermal dysplasia

La displasia ectodérmica hipohidrótica (DEH) es una entidad infrecuente caracterizada por deficiencia en el desarrollo de estructuras derivadas del ectodermo y es causada por mutaciones en los genes EDA, EDAR o EDARADD, que pueden exhibir hallazgos clínicos similares, debido a una vía de señalización común. Las mutaciones en el gen EDA causan la DEH ligada al X, que es la forma más frecuente. Por su parte, las mutaciones en los genes EDAR y EDARADD causan la DEH con patrón de herencia autosómica dominante y recesiva. Los hallazgos clínicos más resaltantes son hipodoncia, hipotricosis e hipohidrosis, que pueden llevar a episodios de hipertermia. Se presentan los hallazgos clínicos en un niño con DEH con patrón de herencia autosómica dominante, cuyo análisis molecular demostró mutación heterocigótica c.1072C>T (p.Arg358X) en el gen EDAR, y se discuten los diferentes aspectos clínicos encontrados en esta mutación en los casos descritos en la literatura.

Hypohidrotic ectodermal dysplasia (HED) is a rare disease characterized by deficiency in development of structure derived from the ectoderm and is caused by mutations in the genes EDA, EDAR, or EDARADD. Phenotypes caused by mutations in these three may exhibit similar clinical features, explained by a common signaling pathway. Mutations in EDA gene cause X linked HED, which is the most common form. Mutations in EDAR and EDARADD genes cause autosomal dominant and recessive form of HED. The most striking clinical findings in HED are hypodontia, hypotrichosis and hypohidrosis that can lead to episodes of hyperthermia. We report on clinical findings in a child with HED with autosomal dominant inheritance pattern with a heterozygous mutation c.1072C>T (p.Arg358X) in the EDAR gene. A review of the literature with regard to other cases presenting the same mutation has been carried out and discussed.

Estudio clínico y molecular en un escolar con displasia ectodérmica hipohidrótica ligada al X / Clinical and molecular study in a child with X-linked hypohidrotic ectodermal dysplasia

Las displasias ectodérmicas comprenden más de 200 entidades clínicamente distintivas, las cuales afectan, al menos, dos estructuras derivadas del ectodermo, que incluyen la piel, el pelo, las unas, los dientes, las glándulas sudoríparas y sebáceas. La displasia ectodérmica hipohidrótica ligada al X es el tipo más frecuente y es causada por mutación del gen EDA, que codifica la ectodisplasina-A. Su frecuencia es menor de 1 en 100000 individuos y se caracteriza clínicamente por presentar hipodoncia, hipohidrosis, hipotricosis y alteraciones oculares. Se expone el caso de un escolar evaluado de forma multidisciplinaria con diagnóstico clínico y molecular de displasia ectodérmica hipohidrótica ligada al X con mutación tipo cambio de sentido c.1133C>,T, p.T378M, en el gen EDA.

Ectodermal dysplasia encompasses more than 200 clinically distinct entities, which affect at least two structures derived from the ectoderm, including the skin, hair, nails, teeth, sweat glands, and sebaceous glands. X-linked hypohidrotic ectodermal dysplasia is the most common type and is caused by mutation of the EDA gene that encodes Ectodysplasin-A. It occurs in less than 1 in 100 000 individuals and is clinically characterized by hypodontia, hypohidrosis, hypotrichosis, and eye dis orders. We present a child evaluated in a multidisciplinary manner with clinical and molecular diagnosis of X-linked hypohidrotic ectodermal dysplasia with type missense mutation c.1133C> T; p.T378M in EDA gene.

Caso para diagnóstico / Case for diagnosis

A síndrome de Christ-Siemens-Touraine (displasia ectodérmica hipoidrótica) é uma síndrome rara, caracterizada pela tríade de sudorese reduzida ou ausente, hipotricose e dentição defeituosa. Bossas frontais proeminentes, nariz em sela, lábio inferior espesso e queixo pontudo fazem com que os pacientes tenham uma fácies característica e semelhante. A síndrome completa ocorre em homens, visto tratar-se de herança recessiva ligada ao X.

Christ-Siemens-Touraine syndrome (hypohidrotic ectodermal dysplasia) is a rare syndrome characterized by the triad of absent or reduced sweating, hypotrichosis, and defective dentition. The prominent forehead, saddle nose, thick lower lip and pointy chin produce a distinctive facies. The full syndrome only occurs in men as it is an X-linked recessive condition.

[Hypohidrotic ectodermal dysplasia: ten cases]

Ectodermal dysplasias are rare hereditary diseases characterised by congenital absence of ectodermally derived structures and classified according to four symptoms: trichodysplasia, hypodontia, onychodysplasia and hypohidrosis. The objective of our study is to precise the epidemioclinical characteristics, the diagnostic tools, the evolution and the treatments of this rare disease through a 10-case series of hypohidrotic ectodermal dysplasia [HED]. The present report is a retrospective study of all cases of an/hypohidrotic ectodermal dysplasia collected from 1977 to 2006. We have specified age, sex, parental consanguinity, similar familial cases, clinical and histological features, dental, oto-rhino-laryngologic, ophthalmologic and respiratory examinations. Ten cases of HED were collected [average age: 14 years, sex ratio 9/1]. The mean duration diagnostic period was of 14 years. Parental consanguinity was registered in 3 cases but only one patient had similar familial cases. All patients had facial dysmorphy, hypotrichosis and hypo/anodontia [respectively 8/10 and 2/10]. All patients had clinically and histologically documented hypoplastic [6/10] or aplastic sweat glands [4/10]. Extra-cutaneons manifestations were noted in 8 patients [recurrent rhinitis 6/10, recurrent pneomopathies 3/10, xerophtalmy 3/10]. Our series deals with 10 cases of HED, consisting in Chris-Siemens Taos-nine syndrome. It highlights the delayed diagnosis of Ibis disease [mean: 14 years] with a diagnosis made at an adult age in four patients. Our study confirm the X-linked heredity [9/10] with a possible autosomal transmission [one female-case]. HED is rarely life-threatening, but early diagnosis allows a better quality of life to patients and genetic counselling to parents. Our series illustrates the rarity of RED which is also probably due to its underestimation by clinicians

Hypohydrotic ectodermal dysplasia.

Hypohydrotic ectodermal Dysplasia (Christ-Siemens Touraine syndrome) is a rare genetic disorder that affect several ectodermal structures. The condition is usually inherited as X-linked recessive trait, in which gene is carried by females and manifested in males. The manifestations may vary in individuals and usually involves skin, hair, nail, sweat and sebaceous glands. Hypohydrotic Ectodermal Dysplasia with classical features in two siblings is reported here.