GENETIC TESTS

Deoxyribo Nucleic Acid, DNA, is the genetic material in our cells which are the building blocks that give the genetic instructions necessary for the vital functions and biological development. 

Our body composed of cells, in cells DNA is contained within structures called chromosomes. There are 23 pairs of chromosomes that we inherit from our biological parents. 22 pairs called autosomes and the last pair is sex chromosomes determined our sex XX or XY. DNA is double-helix structure  contain 3.2 billion nucleotide pairs, these nucleotides are adenine (A), thymine (T), guanine (G) and cytosine (C) and pairs oppositely (A-T : C-G) to connect the 2 DNA strands. The sequence of these bases constitutes the genetic code, DNA, that specifies the order and number of amino acids in a protein. It is a very complex and extraordinary mechanism with it is coding and non-coding regions.  These regions and sequences compose a ''Gene'' and it is estimated that humans have over 20.000 Genes. 

As start of the Human Genome Project, which is another revolution in science, the international researchers, scientists and geneticists effort to determine the DNA sequence of the entire human genome. Primary goal of the HGP was  understanding, discovering and mapping the complete set of human genes beside it becomes a breakthrough to identify inherited diseases, genetic disorders, diagnosis and gene therapies. 

Genetic Testing examines and determines the changes in genetic material, it helps to identify changes (mutations, variants, deletions, exertions) in chromosome structures or in DNA sequences. If any change in these structures some diseases or disorders can occur. 

Many aspects of our body, health and diseases are determined by genetic factors (inherited) and non-genetic factors (environmental), inherited factors are eye color, hair color, some abilities or disease pass through past generations while environmental factors like diets, lifestyle, maternal malnutrition or stress. Some diseases caused by the combination of both called multifactorial ; like diabetes, cancer, Alzheimer. 

Genetic makeup or ''Genotype'' is directly related with being and staying healthy as well as developing a disease or disorder. Genetic diseases can occur in any period of lifetime from pregnancy to birth and aging. 

Genetic testing may help to get information in many ways such as determining biological relatives, diagnosing a genetic condition, initiating prevention from diseases, starting or observing a treatment, family planing as well as our choices like diet, sport or career. 

Genetic Testing provides lots of information to a person and families for their healthcare needs to confirm a diagnosis or to follow up a treatment , for their  long-term needs to prevent a disease and to change life style, for their family planning to locate possible genetic conditions that can be inherited to child or to get child for detecting infertility problems and miscarriages. 

Genetic testing is used in many reasons to get information; genetic testing includes tests like; 

Carrier Testing:  Carrier Testing offered to couples who have a family history of  genetic disorder and to people in some ethnic groups with an increased risk of specific genetic conditions. Sickle Cell Anemia, Muscular Dystrophy, Cystic Fibrosis and Red-green color blindness are some examples of genetic conditions that can pass to children from carrier couples.

Prenatal Testing: Prenatal testing offered during pregnancy to detect if there is an increased risk that the baby will have a genetic or chromosomal disorder. It can be done in non-invasive way (Mother's blood) or invasive ways amniocentesis and chorionic villus sampling to identify inherited disorders like; Down Syndrome, Patau Syndrome or many other genetic diseases. 

Diagnostic Testing:  Diagnostic Testing offered to confirm a diagnosis if the person suspected from a disease and show physical signs and symptoms. It is also used to monitor prognosis of a disease or response to treatment especially in certain cancer types.

Predictive or Pre-Dispositional Testing:  Predictive testing offered to identify persons at risk of getting a disease or develop a genetic disorder before any symptoms occur. It is useful if a person has a family history of a specific disease or disorder for preventing it such as; certain types of cancer, cardiovascular (heart) diseases, dementia or hemochromatosis (iron overload). 

Forensic Testing:  Forensic Testing is not a diagnostic testing unlike the tests described above. It is usually used in criminal investigation and also demanded  to identify biological relationships between people like paternity, sibling-ship.