{"id":1436,"date":"2026-01-25T15:18:49","date_gmt":"2026-01-25T21:18:49","guid":{"rendered":"https:\/\/zogen.local\/?p=1436"},"modified":"2026-01-25T15:18:49","modified_gmt":"2026-01-25T21:18:49","slug":"key-concepts-about-genetics","status":"publish","type":"post","link":"https:\/\/zogen.mx\/en\/conceptos-clave-sobre-genetica\/","title":{"rendered":"Key concepts about genetics"},"content":{"rendered":"
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Key concepts about genetics.<\/p>\n\n\n\n

Genetics is a fundamental pillar of medicine; its study provides valuable information for both disease prevention and diagnosis. Medical genetics is a complex field, and in this blog, we will attempt to explain some basic concepts to improve your understanding of this science and introduce you to its study.<\/p>\n\n\n\n

The first step in starting to talk about genetics is how this information is presented in the organism.<\/h2>\n\n\n\n

The entirety of an organism's genetic information is called its genome and is contained in the form of DNA. DNA is short for deoxyribonucleic acid, a complex molecule found within every cell of our body. The information contained in DNA is coded using a system of four nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G). The basic unit in genetics is the gene, and genes contain the information to produce the proteins that make up our bodies.<\/p>\n\n\n\n

We can distinguish two types of DNA based on their cellular location. The majority type is found in the cell nucleus and is known as nuclear DNA; however, we can also find another type of DNA in the mitochondria called mitochondrial DNA. Nuclear DNA is inherited from both parents, while mitochondrial DNA is inherited only from the mother.<\/p>\n\n\n\n

DNA is packaged by proteins called histones, which together form chromatin. The assembly and disassembly of DNA by histones is key to the regulation and expression of many genes. When cell division occurs, the chromatin becomes highly compacted and forms chromosomes.<\/p>\n\n\n\n

In humans, each human cell has 46 chromosomes, organized into 23 pairs, of which 22 pairs are autosomes and 1 pair are sex chromosomes. In each pair, one chromosome is inherited from the mother and the other from the father.<\/h2>\n\n\n\n

In the case of autosomes, the fact that we have two chromosomes means that we also have two copies of the genes they contain. Each version of these genes is called an allele. If the two alleles are identical for a given position in the genome, the individual is homozygous for that variant, but if they have two different versions, they are considered heterozygous.<\/p>\n\n\n\n

We all have different genetic variations that make us unique. Among the variations we may have, single nucleotide polymorphisms (SNPs) are common, found in more than 11% of the population. In addition to SNPs, we find mutations, which are rare variations present in less than 11% of the population and may be associated with genetic diseases.<\/p>\n\n\n\n

Depending on the tissue in which they occur, mutations are classified as somatic or germline, which will give us the difference between genetic and hereditary diseases.<\/a> Germline DNA is the DNA found in gametes and most cells of the body. Somatic DNA is the DNA of a specific tissue where localized mutations can occur that are not found in the rest of the body. Mutations in germline DNA are inherited and passed on to offspring, while variants in somatic DNA are not.<\/p>\n\n\n\n

When we talk about the genome, we are talking about the total genetic information of an individual.<\/h2>\n\n\n\n

At this point, it is important to remember the central dogma of molecular biology: DNA is transcribed into RNA, and RNA is translated into proteins. The regions of the genome that are transcribed into proteins are called coding regions. The genome contains both coding and non-coding regions. The most important part of the genome is the exome, the coding regions that represent approximately 1-2% of the entire genome.\u00a0The choice between a genome test and an exome test depends largely on the indication for the test.<\/a><\/p>\n\n\n\n

When a failure or change occurs in the DNA sequence, the genetic code is altered, and therefore, protein synthesis is affected. These changes, also known as variants, can take different forms, such as substitutions, deletions, duplications, and inversions, among others. Similarly, there are alterations at the chromosomal level called chromosomal abnormalities, which include the loss or gain of one or more chromosomes (numerical abnormalities), the partial loss or gain of a chromosome, or the presence of a chromosome fragment in an abnormal position (structural abnormalities).<\/p>\n\n\n\n

The genotype is the set of all genetic information that makes up an individual.<\/h2>\n\n\n\n

When a genotype alteration is detected, it is important to determine whether it will manifest in the phenotype, that is, in the observable characteristics of the individual, which may have an impact on their health. There are different types of pathologies with varying repercussions on people's health; generally speaking, we can distinguish the following:<\/p>\n\n\n\n