Seminario 12 Herencia monogénica autosómica dominante y recesiva - Sebastián Giusti

Hello, how are you? In today's class we are going to analyze the classic inheritance patterns. In particular we will analyze the autosomal inheritance patterns related to those diseases of genetic origin. When we talk about monogenic or Mendelian disorders in the context of medical genetics, we are talking about those clinical sets of signs and symptoms

that are determined by the presence in the genome of pathogenic allelic variants that are present in a single gene in the genome. And this adjective, Mendelian, is conferred upon this group of entities because the patterns of manifestation of these entities and also the recurrences throughout the generations follow some principles originally described by

Mendel, which we will try to interpret in this context with some elements of cellular and molecular biology and some specificities that occur in the medical context. For example, the zeroth law or dominance principle as the first Mendelian principle refers to the fact that signs and symptoms, such as the characteristic trait that we will analyze

in the context of these entities that belong to the phenotype, are traits that can be characterized as dominant or recessive. So, these terms dominant and recessive are terms that apply to the phenotype, particular traits that manifest in this particular context. And dominant traits will be those for which the presence of a single

pathogenic variant in the genome is sufficient for it to manifest. In contrast, those characteristics of the phenotype, in particular the manifestation of signs and symptoms, will be recessive if the presence in diploidy of two pathogenic variants of the same gene is necessary, one of maternal origin and the other of paternal origin. So, in that