ABSTRACT
El síndrome de Smith-Lemli-Opitz es una entidad de etiología autosómica recesiva, que cursa con malformaciones congénitas, retraso del crecimiento y desarrollo pre y posnatal y es causa de muerte a temprana edad. No se conoce tratamiento, por lo que solamente se cuenta con el asesoramiento genético para evitar la aparición de nuevos casos.Se presenta el caso de dos hermanos, hijos de padres consanguíneos. Ambos fueron detectados desde el nacimiento y aun cuando se diagnosticaron al mes de vida, el asesoramiento genético proporcionando a los padres no fue efectivo, ya que después del primer hijo afectado tuvieron dos embarazos más, resultando afectado el producto del segundo de éstos. Se ha encontrado una deficiencia en la síntesis de colesterol, por lo que es posible hacer el diagnóstico prenatal en las mujeres que tienen antecedentes de gestas previas con esta enfermedad
Subject(s)
Humans , Male , Infant, Newborn , Female , Pregnancy , Cholesterol/analysis , Cholesterol/metabolism , Cholesterol , Prenatal Diagnosis , Smith-Lemli-Opitz Syndrome/diagnosis , Smith-Lemli-Opitz Syndrome/etiology , Smith-Lemli-Opitz Syndrome/genetics , ConsanguinityABSTRACT
All studies on trichinellosis have been based on the assumption that there is only one cosmopolitan agent of human and animal trichinellosis; Trichinella spiralis (Owen, 1835). In the past, swine and only a few synanthropic animals were considered reservoirs, and the presence of the parasite in sylvatic animals was considered rare. Breeding experiments before, and then biochemical approaches (isoenzymes and DNA analysis), showed the presence of a high genetic variability inside this genus, suggesting it be considered as polyspecific. At present, eight gene pools, named from T1 to T8, have been identified in the genus Trichinella. T1 (T. spiralis s str) is the etiological agent for the domestic cycle, with a cosmopolitan distribution related to swine breeding and human habits. However, in some areas this parasite passes from domestic to sylvatic animals and vice versa. Six gene pools are the agents for the sylvatic cycle at different latitudes, mainly in carnivores. T2 (T. nativa) is present in terrestrial mammals and seldom in sea mammals of arctic and subarctic regions. T3, T5, and T8 are present mainly in Canidae (T3), Ursidae (T5), Hyaenidae and Felidae (T8) of temperate-subtropical areas of Palearctic, Nearctic and South African regions, respectively. T6 is present in carnivores in the subarctic-temperate area of the Nearctic region; and T7 (T. nelsoni) in Hyaenidae and Felidae of Equatorial Africa. Only T4 (T. pseudospiralis) can infect both mammals and birds, and it shows a cosmopolitan distribution. Probably trichinellosis is present world-wide, but unknown in those areas where it has not been sought.