Résumé
Resumen: el síndrome de Werner es una patología poco frecuente, de herencia autosómica recesiva, caracterizado por signos de envejecimiento prematuro y tendencia a desarrollar tumores malignos. El diagnóstico de esta enfermedad es principalmente clínico, con hallazgos predominantes como talla baja y envejecimiento precoz. En este artículo se presenta el caso de un paciente de 49 años de edad, con signos tempranos de envejecimiento desde los 15 años y ateroesclerosis temprana asociada, que lo lleva a amputación quirúrgica de extremidad inferior derecha. De acuerdo con los criterios diagnósticos del síndrome de Werner este es el primer caso probable en el suroccidente colombiano. (AU)
Abstract: Werner syndrome is a rare, autosomal recessive pathology, characterized by signs of premature aging and tendency to develop malignant tumors. The diagnosis is principally clinical, with predominating findings as short stature and precocious aging. In this article, it's presented the case of a 49-year-old patient with early signs of aging from the age of 15 years and associated early atherosclerosis that leads to the right lower limb surgical amputation. According to the diagnostic criteria of Werner syndrome, this is the first probable case in the Colombian Southwest. (AU)
Sujets)
Humains , Vulnérabilité SexuelleRésumé
A síndrome de Werner é uma doença autossômica recessiva rara associada a envelhecimento precoce, cujo quadro cutâneo deve ser distinguido daquele encontrado na esclerose sistêmica (ES). Descrevemos aqui o caso de uma paciente de 39 anos de idade, portadora de síndrome de Werner, encaminhada ao nosso serviço com hipótese diagnóstica inicial de ES. A paciente apresentava várias manifestações associadas à síndrome de Werner, incluindo cabelos precocemente grisalhos, voz estridente, baixa estatura, alterações cutâneas esclerodermiformes, diabetes melito, catarata, hipogonadismo, hipotireoidismo e hiperlipidemia. Não apresentava fenômeno de Raynaud, manifestações viscerais típicas da ES, alterações capilaroscópicas periungueais ou auto-anticorpos. O diagnóstico de síndrome de Werner, apesar de raro, deve ser lembrado no diagnóstico diferencial de ES, principalmente na presença de manifestações atípicas e na ausência de alterações típicas da ES.
Werner's syndrome is a rare autosomal recessive disease associated with premature ageing. Skin alteration must be distinguished from cutaneous manifestation of systemic sclerosis (SSc). We describe a case of a 39 years old patient with Werner's syndrome admitted with an initial diagnostic hypothesis of SSc. The patient had many characteristic features associated with Werner's syndrome including gray hair, hoarseness, short stature, scleroderma-like skin changes, diabetes mellitus, cataracts, hypogonadism, hypothyroidism, and hyperlipidemia. There was no Raynaud's phenomenon, other typical visceral manifestation of SSc, nailfold capillary alterations or autoantibodies. Werner's syndrome diagnosis notwithstanding rare, should be remember in the differential diagnosis of SSc, mainly in the presence of atypical manifestations and in the absence of typical features of SSc.
Sujets)
Humains , Femelle , Adulte , Vieillissement précoce , Progeria , Sclérodermie systémique , Syndrome de WernerRésumé
El nucléolo, considerado únicamente como el sitio de síntesis de los ribosomas, actualmente representa una estructura nuclear dinámica que participa en la regulación de importantes procesos celulares. Numerosas evidencias han demostrado que el envejecimiento celular es una de las diversas funciones que son controladas por el nucléolo. Las mutaciones en las proteínas de localización nucleolar promueven el envejecimiento prematuro en levaduras y humanos. La carencia de represión en la transcripción de genes que codifican para el ARNr que se encuentran dañados, y las mutaciones en las helicasas del ADN encargadas de minimizar la formación de círculos extra-cromosómicos del ADN que codifica para el ARNr, provocan modificaciones en la estructura del nucléolo e inducen envejecimiento prematuro en levaduras. De igual manera, en los humanos la carencia de las helicasas del ADN localizadas en el nucléolo y que participan en el mantenimiento de la integridad genómica, favorecen el desarrollo de aquellas enfermedades asociadas con el envejecimiento acelerado. Además, la presencia de algunos componentes de la telomerasa en el nucléolo, indica que parte de la biosíntesis de esta enzima se realiza en esta estructura nuclear, sugiriendo una conexión entre el nucléolo y la síntesis de los telómeros en la regulación del envejecimiento celular. Por otra parte, el nucléolo secuestra proteínas para regular su actividad biológica durante el inicio o término de la vida replicativa celular.
The nucleolus has been considered originally only as the site for the ribosome synthesis, but now it is well known that it represents a dynamic nuclear structure involved in important cellular processes. Several evidences have demonstrated that the nucleolus regulates the cellular senescence. Specific mutations on the DNAs codifying for nucleolar proteins induced premature senescence from yeast to human. The failure to repress the genes transcription codifying for damaged rRNA, and the mutations in DNA helicases, which minimizes the formation of DNA extra-chromosomal circles codifying for rRNA, modify the nucleolar structure and induce premature senescence in yeast. Similarly, in humans, the reduction of these DNA helicases levels, which are localized in the nucleoli and participate in maintenance of genomic integrity, helps to the development of those diseases associated with premature senescence. Furthermore, the presence in the nucleolus of some telomerase components, indicates that part of the biosynthesis of this enzyme occurred in this nuclear structure; suggesting a communication between the nucleolus and the synthesis of the telomeres in the regulation of cell senescence. On the other hand, the nucleolus sequesters proteins to regulate its own biological activity, from the start to the end of cellular replication. In addition this nuclear structure is involved in the biosynthesis of most cellular ribonucleoprotein particles, as well as in cell cycle regulation, making it central to gene expression. In conclusion, the nucleolus became a multifunctional subnuclear structure involved from cell proliferation to cell senescence.