Genodermatosis hiperpigmentadas

Introducción: Las genodermatosis son consideradas enfermedades raras, por ser poco frecuentes y afectar un número reducido de individuos. El poco conocimiento sobre ellas en el campo de las ciencias médicas y los pobres recursos terapéuticos disponibles dificulta su diagnóstico, con una alta morbilidad. En Las Tunas representan 22,22 % de las enfermedades genéticas. Entre ellas se pueden citar presentando alteraciones de la pigmentación con hiperpigmentación: incontinencia pigmenti, síndrome de LEOPARD, mastocitosis, la neurofibromatosis, síndrome de Noonan, y con hiper e hipopigmentación están las didimosis. Objetivo: Compilar información actualizada acerca de las características y criterios diagnósticos de las enfermedades genéticas nombradas que faciliten su estudio y seguimiento de los pacientes. Métodos: Revisión de la literatura disponible en SciELO, PubMed Central, Medline Plus, Clinical key, Orphanet y OMIM. Los descriptores utilizados fueron: genética médica, enfermedades dermatológicas genéticas. Durante el proceso de revisión se consultaron 7 libros y 16 artículos publicados en los últimos 5 años. Análisis y síntesis de la información: Se revisó la clasificación de las genodermatosis hiperpigmentarias, y de estas las características clínicas, el tipo de herencia, el gen afectado, los criterios diagnósticos y estudios complementarios. Conclusiones: Conocer las características y criterios diagnósticos de las enfermedades genéticas presentadas permite diagnosticarlas, diferenciarlas entre ellas y favorecer el seguimiento de los pacientes afectados.

Introduction: Genodermatoses are considered rare diseases, as they are rare and affect a small number of individuals. The poor knowledge about them in the field of medical sciences and the poor therapeutic resources available hinder their diagnosis, with high morbidity. In Las Tunas they represent 22.22% of genetic diseases. Among them, can be cited presenting pigmentation alterations with hyperpigmentation: incontinentia pigmenti, LEOPARD syndrome, mastocytosis, neurofibromatosis, Noonan syndrome, and with hyper and hypopigmentation are the didymosis. Objective: To compile updated information about the characteristics and diagnostic criteria of the genetic diseases named to facilitate their study and follow-up of patients. Methods: Literature review available in SciELO, PubMed Central, Medline Plus, Clinical key, Orphanet and OMIM. The descriptors used were: medical genetics, genetic dermatological diseases. During the review process, 7 books and 16 articles published in the last 5 years were consulted. Analysis and synthesis of information: The classification of hyperpigmentary genodermatoses was reviewed, and of these the clinical characteristics, the type of inheritance, the affected gene, the diagnostic criteria and complementary studies. Conclusions: Knowing the characteristics and diagnostic criteria of the genetic diseases presented allows to diagnose them, differentiate them between them and favor the follow-up of the affected patients.

Identification of Codon 146 KRAS Variants in Isolated Epidermal Nevus and Multiple Lesions in Oculoectodermal Syndrome: Confirmation of the Phenotypic Continuum of Mosaic RASopathies.

Mosaic RASopathies are a molecularly heterogeneous group of (neuro)cutaneous syndromes with high phenotypical variability. Postzygotic variants in KRAS have been described in oculoectodermal syndrome (OES), encephalocraniocutaneous lipomatosis (ECCL) and epidermal nevus syndrome (ENS). This study confirms the continuum of mosaic neurocutaneous RASopathies showing codon 146 KRAS variants in an individual with OES and, for the first time, in an individual with (isolated) epidermal nevus. The presence of a nevus psiloliparus in individuals with OES indicates that this finding is not specific for ECCL and highlights the phenotypical overlap between ECCL and OES. The presence of the somatic KRAS variant in the nevus psiloliparus resolves the underlying molecular etiology of this fatty-tissue nevus. In addition, this finding refutes the theory of non-allelic twin-spotting as an underlying hypothesis to explain the concurrent presence of two different mosaicisms in one individual. The identification of codon 146 KRAS variants in isolated epidermal nevus introduces a new hot spot for this condition, which is useful for increasing molecular genetic testing using targeted gene sequencing panels.

The categories of cutaneous mosaicism: A proposed classification.

Mosaic disorders can most easily be studied in the skin. This article presents a comprehensive overview of the different forms of cutaneous mosaicism. Major categories are genomic versus epigenetic mosaicism and nonsegmental versus segmental mosaicism. The class of nonsegmental mosaics includes single point mosaicism as exemplified by solitary benign or malignant skin tumors; disseminated mosaicism as noted in autosomal dominant tumor syndromes such as neurofibromatosis 1; and patchy mosaicism without midline separation as found in giant melanocytic nevus. The class of segmental mosaics includes segmental manifestation of lethal genes surviving by mosaicism as noted in Proteus syndrome; type 1 segmental mosaicism of autosomal dominant skin disorders reflecting heterozygosity for a postzygotic new mutation; type 2 segmental mosaicism of autosomal dominant skin disorders reflecting loss of heterozygosity that occurred at an early developmental stage in a heterozygous embryo; and isolated or superimposed segmental mosaicism of common polygenic skin disorders such as psoriasis or atopic dermatitis. A particular form of genomic mosaicism is didymosis (twin spotting). Revertant mosaicism is recognizable as one or more areas of healthy skin in patients with epidermolysis bullosa or other serious genodermatoses. The category of epigenetic mosaicism includes several X-linked, male lethal disorders such as incontinentia pigmenti, and the patterns of lyonization as noted in X-linked non-lethal disorders such as hypohidrotic ectodermal dysplasia of the Christ-Siemens-Touraine type. An interesting field of future research will be the concept of epigenetic autosomal mosaicism that may explain some unusual cases of autosomal transmission of linear hypo- or hypermelanosis.

Co-occurrence of hemiscrotal agenesis with cutis marmorata telangiectatica congenita and hydronephrosis affecting the same side of the body.

To our knowledge, there are nine previous reports of patients with congenital scrotal agenesis (CSA), seven of which were bilateral, and unilateral in two, also named as hemiscrotal agenesis (HSA). Here, we report a male infant with the previously undescribed co-occurrence of HSA with cutis marmorata telangiectatica congenita (CMTC), and hydronephrosis due to vesicoureteral reflux, all of them on the left side. CMTC is a segmental vascular malformation usually attributed to mosaicism of a postzygotic mutation, whereas the mechanisms in the CSA involve a failure on the labioscrotal fold (LSF) development due to a localized 5α-reductase deficiency and/or androgen insensitivity. Since the skin with HSA was affected also by CMTC and by the fact that it exhibited lack of response to the topical testosterone treatment, all this suggests to us an androgen insensitivity mosaicism in our patient restricted to the left LSF, because skin with intact androgen receptors normally shows some type of response. Since CSA and/or HSA have been also seen in patients with PHACES, popitleal pterygium syndrome, or as part of a recently proposed familial entity with CSA (or agenesis of labia majora as its female counterpart), developmental delay, visual impairment, and moderate hearing loss, further reports could confirm this manifest genetic heterogeneity, highly evocative of somatic mosaicism in our patient.

Facomatosis pigmentovascularis: revisión y nueva clasificación / Phacomatosis pigmentovascularis: review and new classification

La facomatosis pigmentovascularis es un síndrome infrecuente caracterizado por la asociación de un nevus vascular con un nevus pigmentario. Su etiología es desconocida. Se ha propuesto un modelo genético de didimosis o manchas gemelas. La clasificación previa establece cinco categorías, que a su vez se subdividen en a) cuando existe compromiso cutáneo y b) cuando existe compromiso cutáneo y sistémico. Se ha propuesto una nueva clasificación, más simple, que resume las 10 categorías previas en tres tipos definidos: facomatosis cesioflammea, facomatosis spilorosea y facomatosis cesiomarmorata. Además, agrega un cuarto tipo de FPV no clasificables. Se han descrito asociaciones con otras alteraciones de la piel, oculares, vasculares, neurológicas, inmunológicas y malformaciones, por lo cual es recomendable realizar un examen físico extenso y derivación a especialidades para descartar patologías asociadas. Presentamos el caso de una mujer de 27 años que presenta lesiones correspondientes a una facomatosis cesioflammea en la nueva clasificación.

Phacomatosis pigmentovascularis is an uncommon syndrome characterized by the association of a widespread vascular nevus with a pigmentary nevus. Its etiology is unknown. A twin spotting or didymosis genetic model has been proposed. The previous classification established five categories, further subdivided into a) when cutaneous involvement was present or b) when cutaneous and systemic involvement was present. A new, more straightforward classification has been proposed, which summarizes the ten previous categories into three distinct types: phacomatosis cesioflammea, phacomatosis spilorosea and phacomatosis cesiomarmorata. Furthermore, a fourth category of unclassifiable phacomatosis pigmentovascularis was added. Diverse associations of phacomatosis pigmentovascularis with other skin lesions, malformations, and ocular, vascular, neurological and immunological abnormalities have been described, hence the importance of an extensive physical examination and consultations to discard associated pathologies. We present the case of a 27 year old woman, diagnosed with phacomatosis cesioflammea, based on the new classification.