What is Genetic Testing?

November 12, 2012

What is Genetic Testing?

Genetic testing may be carried out to establish if a person has a genetic disease or condition or is at risk of developing one.

Certain groups of people who would want genetic tests carried out may be those with a family history of an illness/disease, have concerns on passing on a genetic disease to children or have symptoms appearing which may be from a genetic disorder.

Genetic tests include techniques to examine genes or markers near the genes.

Testing for sickle cell anemia and cystic fibrosis would involve precise analysis of the patient’s genes and this is known as direct testing.

Indirect testing or linkage analysis is a technique used if the gene cannot be identified directly but it can be found in a specific area of a chromosome. Apart from identical twins no two people have the same DNA, it is completely unique. Genetic tests can also be carried out for identification purposes and is commonly known as DNA finger printing.

Carrying out genetic tests is very complex and is dependent on the accuracy of interpreting the results and also the reliability of the processes and procedures within the laboratory environment.

There can be a variance in sensitivity of genetic tests which means that there is an inability to identify mutations or be able to identify patients who have or are at risk of having a particular illness/disease.

Trained medical staff can find interpreting the results of a genetic test difficult. Factors which have to be taken into consideration when analyzing the results from the genetic tests are the chances of a false positive or false negative result. Specially trained staff will communicate and explain in detail to patients and families on what to expect when having a genetic testing and how to interpret results.

Carrier identification is one of a variety of tests that is used by couples if they have a family history of recessive genetic disorders and are considering starting a family. The three common tests which are carried out are Sickle-cell, Tay-Sachs disease and cystic fibrosis.

Another genetic test is prenatal diagnosis of a fetus. This would happen if there was any risk of a genetic disease. Testing for the presence of Down syndrome is a common test.

Screening of newborn babies is carried out as a preventative measure in many areas.

Late onset disorders that include heart disease and cancer are difficult to test for as environment and genetics both play a part. Genetic tests may indicate that a patient could be susceptible to these diseases. Huntington’s disease which is caused by a single gene can develop later and tests can be carried out at any time.

DNA testing may be used in criminal investigations and can also be used should disasters, wars and major accidents occur for identification purposes.

Information from genetic tests can seriously affect patients and families and privacy is absolutely crucial in handling any data on the susceptibility or confirmation of a genetic disorder.

Many of the tests that are carried out are on fetuses and new born babies. And if they were found to either be a carrier or may develop an inherited their future could be affected, e.g. getting a job or problems with insurance.

Before having a genetic test it is very important to be aware of the benefits, risks, effectiveness and alternatives to understand the full implications involved.

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