What is meant by genetic disease and how does it occur?
The human body consists of a group of organs, and each organ consists of a huge number of cells, and each cell contains 46 chromosomes located in the cell nucleus in the form of identical pairs, including two pairs that are responsible for determining sex, which are the X and Y chromosomes. In a male, there is an In females, there are two XX chromosomes.

What is a chromosome?
A chromosome is a group of proteins put together, each of which is called a gene, and it is called a gene in English. Each chromosome contains millions of genes.
Every gene is responsible for one or more characteristics in the body. There is a gene for eye color, skin color, etc. When fertilization and pregnancy occur, half of the chromosomes come from the mother through the egg containing 23 chromosomes, and the other half from the father through the sperm containing another 23 chromosomes. By meeting the egg with the sperm, the fertilized egg is formed, which develops into the embryo and then the fetus. Thus, the child takes part of the father’s characteristics and part of the mother’s characteristics.

What is a gene or gene?
Gene is a group of proteins called DNA, and the gene is the basic and functional unit of human heredity.

Is the chromosome formula useful in diagnosing hereditary disease?
In general, the chromosome formula is not useful in diagnosing hereditary diseases, and it is rare to see a hereditary disease resulting from a defect in the number or shape of chromosomes, as most hereditary diseases result from a defect in the genes, not the chromosomes. An example of this is Down syndrome, which is caused by the presence of an extra chromosome in the Husband 21, it is not considered a hereditary condition.
Rare examples of diseases being inherited as a result of chromosomal abnormalities are some types of cancer.

How does genetic disease occur?
Hereditary disease occurs as a result of a defect in the arrangement of the amino acids that make up DNA, which gives the disease a distinct gene.

When is the disease hereditary?
A disease is hereditary when the characteristics of this disease are transmitted from the father or mother, or both, through genes afflicted with a defect such that this defect leads to the occurrence of the disease’s phenomena. Some genetic diseases that are inherited in an autosomal recessive manner may be absent in generations, and then appear when two parties carrying the causative genes marry. .

Can a hereditary disease occur as a result of a chromosomal defect?
This is possible, but rare, as most genetic diseases result from defects in genes, not chromosomes.

What are the patterns of inheritance of autosomal recessive genetic diseases
The word recessive means that it requires a gene from both the father and mother in order to cause the disease, and the word autosomal means that it is related to the autosomal chromosomes and not the sexual ones, so it can affect both sexes. The presence of one gene causes a condition called a carrier of the gene, or a carrier of the disease but not affected. In order for the parents to give birth to an affected child, they must That each of them is a carrier of the gene, and for this reason these diseases are not seen in all generations, as they may disappear and reappear when the gene carriers meet, and the probability of giving birth to an affected child in each pregnancy is 25%.

Autosomal dominant inheritance
The word dominant means that the presence of one gene from one parent is sufficient for the disease to appear in the child to whom this gene was transmitted. Therefore, the condition appears in all generations successively, and affects both sexes, and the probability of giving birth to an affected child is 50% in each pregnancy.

Sex-linked inheritance
It results from a defect in the genes located in the

Multifactorial inheritance
Many of the characteristics that characterize a person - such as weight, height, and blood pressure - are not the result of purely genetic factors that the person inherited from his parents or grandparents.
These characteristics are the result of the interaction of genetic and environmental factors with each other. Environmental factors mean all factors that are not acquired by genetics.
Usually, traits or diseases with multiple causes are acquired by a person if he has a genetic predisposition and is exposed to environmental factors that cause the disease.

How are genetic diseases diagnosed?
The diagnosis can be made based on the patient's story, the family history of the case, and some complementary radiology and laboratory examinations. Some cases need to investigate the responsible genes by conducting a study and genetic counseling. It is important to know the study of ploidy in its general form, as the chromosome count does not diagnose hereditary diseases.

What is the treatment for genetic diseases?
Every disease is treated according to the defect that causes it, and there is no treatment for the cause of the disease yet, that is, the defect cannot be corrected at the genetic level, but rather the problems resulting from it can be treated. It is worth noting that there are ongoing studies on gene therapy.