The genes are the smallest unit of information that is contained in each of our characters. Each individual has a gene from the mother and another from the father that form a character (phenotype) of which one of them is dominant, so it will predominate over the other gene (recessive) and will be noticeable.
Phenotypes are created by the synthesis of proteins, and in the genes it is “written” how this process should be carried out. When there is a genetic disease, it means that this information was not correct, that there was a problem with one of the genes and therefore an alteration is created in the organism.
DNA is the largest genetic structure we have. This molecule is divided into 23 pairs of chromosomes that contain many genes, each pair of chromosomes is made up of one inherited from the mother and the other from the father. Genetics can give answers to the appearance of alterations in chromosomes.
Although there are many debates about the scope of genetics, there is no doubt that their contributions to science have been wonderful. You have been able to discover important information about the evolution of species and how to find solutions to congenital problems or diseases.
Types of genetic inheritance
- Autosomal dominant. The altered allele is the recessive one, and with a single copy the disease occurs.
- Autosomal recessive. The altered allele is the recessive one, but with a single copy, the disease does not occur.
- Dominant, linked to the X chromosome. When the dominant gene is the altered one and is located on the X chromosome, and with only one copy, the disease occurs.
- X-linked recessive . When the recessive gene is the altered one and is on the X chromosome, and with a single copy, the disease does not occur.
- De novo mutation. Appears for the first time in the family.
- Alteration in mitochondria. They are inherited from the mother.
- Sex-linked inheritance. It occurs when alleles are found on the 23rd pair of chromosomes. If that pair has the sign “XY” it is male, and if it is “XX” it is female.
Examples of genetics
Next, we will mention some of the genetic disorders, diseases and inheritances that are studied by genetics.
- Huntington’s disease.
- Cystic fibrosis.
- Sickle cell anemia
- Colour blindness.
- X fragile syndrome.
- Marfan syndrome.
- Congenital insensitivity to pain with anhidrosis.
- Proteus syndrome.
- Netherton syndrome.
- Moebius or Möbius syndrome.
- Down’s Syndrome.
- Turner syndrome.
- Tay-Sachs disease.
- Duchenne muscular dystrophy.