The bottom line for humans is that DNA testing can be used for diagnostic purposes for many diseases. These tests involve taking a material, which is usually blood, and detecting various mutations, or errors, in it.
In recent years, we’ve been hearing a lot about DNA and related concepts such as gene, mutation, and cloning.
How DNA is built
It is a double-stranded chain of deoxyribonucleic acid, twisted in a helical fashion. One of the components of these strands are chemical compounds called bases.
There are 4 bases in DNA called respectively:
- adenine (A),
- guanine (G),
- cytosine (C),
- thymine (T).
The bases from each chain pair up respectively:
- adenine with thymine
- guanine with cytosine.
The order of these pairs in the DNA chains forms the so-called genetic code. This is information about the structure of individual proteins of an organism. Errors in the code, or mutations, include the replacement of one base pair with another, or the loss of one or more base pairs from the chain. The code is then misread, and thus the protein encoded by the code segment is incorrectly constructed and changes its properties.
Use of DNA
- Detection of susceptibility to particular diseases
- Enabling the diagnosis of genetic diseases
- Establish paternity
- to help the police find the perpetrators (by testing the DNA from traces left behind, such as cigarette butts, blood or sperm traces, and comparing them with the suspect’s DNA).
- DNA testing is also used in the diagnosis of certain microorganisms. In the last 4 years in Poland there have been many centers where you can do DNA tests privately.
Diseases diagnosed by DNA tests
- Cancer diseases:
BRCA 1 and BRCA 2 gene mutation – is responsible for susceptibility to inherit breast and ovarian cancer; the test is recommended for: people who have a family history of malignant neoplasm in at least two generations; women who have a family history of breast cancer before the age of 50; women who have breast or ovarian lesions
HPV, or human papillomavirus diagnosis – this virus causes cervical cancer or pre-cancerous lesions; testing recommended for women between the ages of 20 and 59
HTGR – detects mutations of genes of repair proteins sensitive to sex hormones; damage to these genes increases the risk of breast, thyroid, ovarian and colorectal cancer; this test is recommended for women taking hormonal contraceptives
- diagnosis of genetic diseases:
- hemochromatosis
- cystic fibrosis
- muscular dystrophy
- Parkinson’s disease
- Alzheimer’s disease.
- diagnosis of microorganisms:
- Chlamydia Trachomatis – bacterium that causes genital diseases
- Chlamydia Pneumonice – bacterium causing respiratory infections
- Toxoplasma gonidii – protozoan causing miscarriages, infections and even fetal death
- Mycobacterium Tuberculosis – diagnosis of tuberculosis at an early stage
- HSV – diagnostics of the virus that causes herpes
- HBV, HCV – diagnosis of the viruses that cause hepatitis.
Procedure of DNA testing
The test involves collecting material from the patient for examination, usually blood. This material is tested and the results are ready after about 10 days, depending on the type of test. The results are kept strictly confidential and available only to the patient.