Cystic fibrosis

 what is cystic fibrosis?

Cystic fibrosis is a genetic disease, that is to say, due to the presence of a defective gene. It is transmitted in an autosomal recessive mode, which means that this altered gene must be present in both parents. To develop cystic fibrosis, must have two mutated genes. There are so many "healthy carriers" in perfect health because they have only one defective gene.

The cause of the occurrence of the disease cystic fiber is the Remove of three consecutive nitrogen bases (AGA) in the DNA molecule, Where AG has been removed from the codon  number 5 and A from the codon number 6, which leads to the no appearance of amino acid number 6 (phenylAlanine). This imbalance results in a change in the resultant protein in a region of functional importance making it not doing its job.

Symptoms of the disease manifest in : Disturbances in cellular exchanges Which leads to thick mucus secretion So stop breathing and digestive functions of the cells of the person affected.

Sickle cell anemia

Sickle cell anemia is an inherited blood disease. It is particularly common in populations from sub-Saharan Africa, the Caribbean, India, the Middle East and the Mediterranean basin.

The characteristics of the different levels of the phenotype of sickle cell disease are:

- At the organic level: severe anemia, weakness, respiratory disorders, heart attack and blood (blood circulation is Unusual).

- At the cellular level: the low number of red blood cells, Change its shape (crescent, or sickle), this latter leads to the blockage of blood vessels and thus non saturate tissue of blood

- At the molecular level: Hemoglobin in the lack of oxygen is less soluble, forming a solid grid of fibers in the cytoplasm of erythrocytes.

Genetic mutation

Genetic mutation

A genetic mutation is a change in the DNA sequence of a gene. This results erroneous information in making proteins. Thus, proteins are absent, deficient or inadequate.

Causes genetic mutations

This change of the genetic information may cause, during the translation of the DNA, the production of a protein does not function properly. These genetic mutations may be due to both external and internal factors:

- Internal factors generate mutations called spontaneous mutations occurring during cell replication.

 In general, they are rare and random, and therefore they are the main source of genetic diversity, engine of evolution. The causes of spontaneous mutations are unknown.

- Possible external factors are physical or chemical compounds; they can significantly increase the rate of mutations in certain circumstances. They are called mutagens, such as electromagnetic waves (X rays, gamma rays, ultraviolet rays), cigarettes, alcohol, or chemical substances like pesticides, benzene derivatives, solvents, colchicine, (they cause an alteration in the number of chromosomes).

If a mutation affected the sex cells (called germ), it is transmitted to the descendants of the mutant individual. The new gene sequence is then called an allele. In some cases, this mutation may provide a selective advantage or otherwise be defective.

This is the basis of the process of evolution (this is the natural selection).

However, for most accidental mutations (caused by irradiation or chemicals), if it affects non-sex cells (called somatic), mutation is not transmitted and affects only the subject having suffered directly. If there is an uncontrolled overproduction of cells, there is the possibility of creating a tumor may develop into cancer. On the contrary, the effect without excessive division is negligible. So, in conclusion, some of these mutations can be harmful to the human body causing serious illnesses can be fatal.