Genetic diseases are those that involve alterations in the genetic material, that is, in the DNA.
Some of them may have a hereditary character, being passed on from parents to children.
However, not every genetic disease is hereditary. An example is cancer, it is caused by changes in genetic material, but it is not transmitted to offspring.
Types
There are three types of genetic diseases:
- Monogenetic or Mendelian: When only one gene is modified.
- Multifactorial or Polygenic: When more than one gene is affected and interference from environmental factors still occurs.
- chromosomal: When chromosomes undergo changes in their structure and number.
For example, we know that the human species has 23 pairs of chromosomes, if there is a lack or excess of one of them, a genetic disease arises.
What are the most common genetic diseases?
The main genetic diseases in humans are:
Down's syndrome
THE Down's syndrome it is a genetic alteration caused by the presence of an extra chromosome in pair 21.
Patients with the syndrome have muscle weakness, ears that are shorter than normal, mild mental retardation, and short stature.
sickle cell anemia
Sickle cell anemia is a genetic alteration with a hereditary character, in which red blood cells lose their normal shape and acquire a sickle shape.
This condition hinders the passage of red blood cells through blood vessels and compromises tissue oxygenation.
Diabetes
Diabetes is a disease that compromises the production of the hormone insulin, responsible for controlling the blood glucose level.
In Brazil, approximately 7% of the population has diabetes.
Cancer
Some cancers are caused by genetic factors. The term represents a set of diseases that are characterized by disordered cell growth that can spread throughout the body.
color blindness
O color blindness it is a sex-linked inheritance, specifically the X chromosome. It is characterized by the inability to distinguish colors such as red and green.
Learn more, read also:
- Genes and Chromosomes
- Introduction to Genetics
- gene therapy
rare genetic diseases
Some genetic diseases are extremely rare, that is, they have a low incidence in the population. Get to know some of the best known:
Duchene muscular dystrophy
Duchene muscular dystrophy is recessive and X-linked. It is characterized by the absence of the dystrophin protein, which leads to muscle weakness.
Cystic fibrosis
Cystic fibrosis is an autosomal recessive inheritance characterized by the production of secretions that accumulate in the lungs and pancreas.
Patau Syndrome
THE Patau's syndrome or trisomy 13 is caused by the presence of an extra chromosome in the number 13 pair.
The disease can cause a number of physical and physiological changes.
Turner Syndrome
THE turner's syndrome is a genetic disease characterized by the presence of only one sex chromosome X, which gives rise to the following karyotype 45, X. Therefore, it only affects female individuals.
The disease affects 1 in every 3,000 births of women. Furthermore, the abortion rate can reach up to 97%.
albinism
Albinism is an autosomal recessive disease. It compromises the production of melanin, the pigment responsible for coloring the skin, eyes and hair.
Therefore, affected people have very white skin, in addition to light hair and eyes.
phenylketonuria
Phenylketonuria is an autosomal recessive inheritance. The disease prevents the metabolism of the amino acid phenylalanine, which accumulates in the blood and can compromise some body functions, especially in the brain.
progeria
Progeria manifests itself in childhood and is characterized by accelerated aging, which can be up to 7 times faster than natural.
It is estimated to reach 1 in every 8 million births. It is common for people with the disease to live to be 15 years of age.
Hypertrichosis
Hypertrichosis is a very rare condition, characterized by excessive hair growth, which covers practically the entire body.
It is estimated that hypertrichosis affects 1 in every 1 billion births.
Also know about the Degenerative diseases.
