Chromosomal aberrations and their variations.

Gabriele Ester Sales

Rogéria Maria Ventura

Abstract

The human species has a total of around 46 chromosomes, 22 pairs of autosomes and 1 pair of sex chromosomes. However, when a chromosomal aberration occurs, it means that these chromosomes undergo a structural or numerical change, which affects the genes. There are two types of chromosomal aberrations: Numerical, when there is a change in the number of the chromosome, which are divided into Euploidies and Aneuploids. And structural chromosomal aberrations when one or more chromosomes present a change in structure, are of four types: Deletion, Duplication, Inversions and Translocation. Despite the incredible precision in which meiotic division occurs, chromosomal aberrations still occur, some of which bring some type of economic benefit when it comes to agriculture, but when this occurs in humans, they unfortunately end up being responsible for several genetic malformations. Some examples of numerical chromosomal aberrations are well known, such as Klinefelter, Turner, Down, Edwards, Patau Syndrome, among others. And in the structural ones we see Cri-du-Chat Syndrome (Cat Scream or Meow Syndrome) and its sister Syndromes: Angelman (of maternal origin) and Prader-Willi (of paternal origin). These syndromes are caused due to genetic alterations that occur in chromosomes, each syndrome with its own peculiarities, which makes identification a little easier, as it is not just about chromosome numbers but also the physical, morphological and clinical appearance of the individual, influencing how they will interact in society