Today, private clinics and specialized firms offer various genetic tests. We will tell you in what cases genetic tests are really necessary and useful, and when they will be stressful and a waste of money.
Any genetic analysis – decoding a person’s DNA and interpreting the results – consists of several stages. Genetic material is taken from cells: they used to work with blood, now laboratories are increasingly switching to non-invasive methods and isolating DNA from saliva.
The isolated material is sequenced – using chemical reactions and analyzers, it is determined in what sequence the monomers are located in it: this is the genetic code. The obtained sequence is compared with the reference ones and certain regions corresponding to certain genes are searched for. Based on the presence or absence of genes or their changes, a conclusion is made about the test result.
Running a sequencer – a device that decodes a DNA sequence – is very expensive due to the large number of chemicals required. In one run, you can decipher many DNA samples, but the more there are, the less reliable the result will be for each sample and the lower the accuracy of the genetic test will be. Therefore, you should contact a trusted laboratory, which will not save on the quality of the analysis by increasing the number of samples.
An important point to consider when obtaining the results of genetic analysis: genetics does not determine everything that happens to our body. Lifestyle and environmental factors play an equally important role – the ecological situation, climate, the amount of sunlight and others.
Below are the main cases for which modern genetic testing is applied.
When is DNA testing used? Health issues
First of all, genetics is designed to help in the treatment and prevention of diseases. There are three main groups of cases when genetic analysis will help to clarify the diagnosis or prevent a possible disease.
Diagnostics of viruses and bacteria by the presence of their DNA in the blood
- Indications. For those who suspect they have a viral or bacterial infection. So, for example, borreliosis can be diagnosed with a tick bite – a disease with a wide range of symptoms.
- How it works. The DNA of organisms that cause disease is different from that of humans. A blood test is taken from the patient and it is determined whether there is foreign genetic material there.
- What is important to consider. These are relatively inexpensive tests, because it does not require decoding of the DNA itself, you just need to determine its presence or absence. Such a test will be more accurate than, for example, a search for antibodies (they appear in the blood only after the incubation period), but it is possible only if a specific disease is suspected.
Diagnostics of existing diseases
- Indications. As a rule, these are complex cases or chronic ailments, the cause of which is not obvious. Then doctors look for possible causes of the disease in the genes and, based on the results, can more accurately diagnose and adjust the treatment.
- How it works. Genetic material can be obtained from any patient’s cells, including material taken for other analyzes. After decoding the DNA, damaged genes are looked for in the sequence. As a rule, this is not a “blind” search along the entire length, but a study of previously known areas.
- What is important to consider. Gene diseases – those that occur due to mutations of just one gene – are quite few. About 92% of diseases that can be found in DNA are multifactorial. This means that mutation is not the only cause of the disease, and adjusting other factors, such as diet or climate, can make it easier to progress.
Prevention of hereditory diseases
- Indications. Doctors can recommend such an analysis to healthy people who have had repeated cases of various diseases among their relatives, such as, for example, most types of cancer, diabetes mellitus and coronary heart disease. That is, those same multifactorial hereditary diseases, which are also called “polygenic with a threshold effect.” Another similar analysis can reveal the likelihood of developing allergies, help adjust the diet depending on the genetic basis of metabolism and select the optimal physical activity.
- How it works. In addition to mutations, doctors can also pay attention to gene variations – alleles. When testing for predispositions to certain diseases, a specific section of DNA is analyzed. Comprehensive screening for a range of potential hereditary diseases can involve the entire genome.
- What is important to consider. These diseases are called “with a threshold effect” for a reason. This means that the disease will develop only after the body reaches the “threshold”. The task of prevention is precisely to prevent this from happening. That is, a positive test for susceptibility to breast cancer does not mean that it will 100% happen. Such a result rather serves as a recommendation to be more attentive to yourself, to avoid risk factors and not to neglect regular examinations by a mammologist.
When people want to have a child, they think about his or her future health. Genetic tests can help in two stages – when planning a pregnancy and during its course.
- Indications. Such a test will help to find out whether the child will inherit “dormant mutations” and the risks of congenital abnormalities. This is important if there are frequent cases of some kind of disease in the family history of the father and / or mother, or if one of the parents actually has a disease.
- How it works. In essence, such tests do not differ from detecting predispositions to diseases in adults, but they simultaneously analyze two parental genomes.
- What is important to consider. The complexity of the analysis lies in the fact that it is impossible to find out in advance which genes of the parents will get the child, this is a kind of lottery. Genes always work in a complex, which makes the number of variations in the genome of the unborn child infinite. That is, the test for heredity of the planned offspring is always probabilistic, and even the presence of “bad” mutations in the parents does not make the birth of a healthy baby impossible.
- Indications. This analysis is performed during pregnancy and is needed if congenital abnormalities are suspected. Also, prenatal genetic diagnosis can determine the sex of the unborn child at an early stage of pregnancy and establish paternity.
- How it works. For prenatal diagnosis, there are several methods of taking a sample of genetic material, the main of which are chorionic biopsy (taking a piece of fetal tissue) and amniocentesis (taking a sample of amniotic fluid). Recently, it is also practiced to isolate the DNA of the embryo from the mother’s blood – a non-invasive prenatal DNA test (NIPT). With in vitro fertilization, preimplantation diagnostics is also possible – DNA is isolated from the embryo cell before it is introduced into the uterus.
- What is important to consider. Invasive methods are always risky. So, the probability of spontaneous abortion after a biopsy reaches 15%, and amniocentesis can lead to infection or detachment of the membranes of the fetus. Both of these methods become possible at a relatively late stage of pregnancy, when the fetal bladder is formed and the embryo is well distinguishable on ultrasound, so they should only be used if there are serious suspicions of genetic or chromosomal defects. Non-invasive diagnostics do not have these consequences and can be performed from the ninth week of pregnancy.
Identifying talents and inclinations
- Indications. Often, genetic testing companies also ask parents to identify the predisposition of children to certain sports or other activities. Such a test can be useful for young athletes before starting a serious career: according to researchers, 60% of sports success is determined by genes.
- How it works. The analysis is carried out in the same way as for determining hereditary diseases, only other sections of DNA are examined. To date, about 50 genes are known that are associated with a predisposition to engage in various sports. It is more difficult with other human talents: for example, a partial genetic nature of absolute pitch has been established, but for the most part this direction is under study.
- What is important to consider. Despite the widespread belief that our genes prescribe certain talents and character traits for us, the genetic basis of the psyche is the most underexplored area in human genetics. Not only diseases can be polygenic – these are most of the traits in the body (for example, eye color is determined by 15 genes). Information taken out of context may turn out to be not only incomplete, but in principle false: it is impossible to determine by one gene whether a child will become an outstanding athlete or not. As for intellectual abilities and character traits, it still lies in the field of assumptions. Finally, if the result of a genetic test “predicts” the child’s success in some path, this can exert psychological pressure on the parents and prevent the child from deciding on his or her own plans for the future. Genes are a recommendation, not a direct indication.
Finding out the origin
- Indications. Genealogical research grew out of forensics and the popular task of establishing paternity. Today, with the help of genetics, both the determination of the closest relatives and the identification of the ancestral group are available. Such an analysis serves to solve applied problems of establishing kinship (this is important for such legal issues as inheritance claims) and may interest simply curious people who study family history.
- How it works. In the course of life, every person accumulates small changes in DNA – not only in genes, but also in the “non-working” part (and the proportion of this in our cells is more than 90%). In genealogical genetic analysis, researchers compare the resulting DNA for similarities with others – either with the DNA of potential relatives, or with a large database. Such databases can include both ancient DNA and the genetic material of the country’s inhabitants. Depending on the country and the genetic laboratory’s access to databases, the picture of the analysis may differ in completeness and detail.
- What is important to consider. Unlike previous analyzes, when the patient’s DNA was compared with a standard, this is a comparison with the genetic material of other people. This procedure raises questions of confidentiality and requires complex legislative regulation. In Iceland, a genetic database has been collected, which contains the decoded DNA of all citizens and permanent residents (the corresponding law was adopted in 1997).
Genetic research is able to provide you with accurate information about the genetic characteristics of both yours and your child. For some people, such a resolution of uncertainty is very important, even if the news received is bad. If the news is good, it can be a huge relief.
Genetic testing can help diagnose a hereditary disorder. Once a person is diagnosed with an accurate diagnosis, adequate treatment may be offered. If genetic testing shows that you have an increased risk of developing a medical condition during your lifetime (such as breast cancer), you may be offered a routine screening program to minimize your risk.
The results of genetic research can provide useful information when planning a future child. If you or your partner are known to have a high risk of having a child with a hereditary disease, it is possible to conduct an examination of the unborn child during pregnancy (prenatal diagnosis) to find out if he or she is sick. Knowing that you are at increased risk of having a child with a hereditary illness may help you to be better prepared mentally and practically.
Since hereditary diseases are often transmitted within the family, information about your genetic characteristics may be useful to other family members. If your relatives know that a hereditary disease is transmitted in the family, this can help to avoid misdiagnoses and wasted time. This information can also be useful to them when planning a child.
Potential risks and limitations
Doing a genetic test, waiting for the results, and then receiving them can cause a wide range of different feelings, such as relief, fear, anxiety, or guilt. It is important to try to perceive both good and bad news in the context of the possible consequences for you and your family.
Even if a genetic test can confirm the diagnosis, it may be that there is no route of action or treatment for that particular disease.
In some people, gene or chromosomal changes (mutations) are not detected. This does not necessarily mean that they are not. Some genetic changes are extremely difficult to detect with modern laboratory methods. In such cases, trying to clarify the diagnosis can be very frustrating. You should discuss this with your doctor.
For some conditions, even the identification of an altered gene or chromosome does not allow us to say how difficult the disease will be in a person.
Genetic mutations are often passed down from generation to generation. Thus, the results of your genetic test may reveal the genetic information of other family members, especially their own risk of inherited disease. Will family members want to know about this?
It may be important to understand how the results of a genetic test might affect your insurance or professional employment before deepening the test.
Research findings can sometimes reveal family secrets, including parenting and adoption issues.
Once a genetic study has been done and the results obtained, they cannot be changed.
Below is a list of average prices for gene tests:
- Dominant / Single Amplicon – $300 8 Various
- Recessive / Dual Amplicon – $300
- Prenatal Diagnosis including Maternal Contamination – $1000
- Prenatal Diagnosis without Maternal Contamination – $800
Inherited Cancer Gene Panel Testing
- Ataxia Telangiectasia – $1300
- Birt-Hogg-Dubé Syndrome – $1300
- Breast Cancer – $1000
- Cowdens – $1300
- Familial Adenomatous Polyposis – $1300
- Lynch Syndrome/Hereditary Nonpolyposis Colorectal Cancer – $1600
- Hyperparathyroidism – $1000
- Legius Syndrome – $600
- Li-Fraumeni Syndrome – $1300
- Multiple Endocrine Neoplasia – $1300
- RET (Type 2A/2B) $1000
- Neurofibromatosis – $1600
- Hereditary Paraganglioma-Pheochromocytoma Syndromes – $1300
- Peutz-Jeghers Syndrome – $1300
- Proteus Syndrome – $1300
- Retinoblastoma – $1300
- Tuberous Sclerosis – $1600
- Von Hippel Lindau Disease (VHL) – $1300
Inherited Cardiac Panel Testing
- Aortopathy subpanel – $1000
- Cardiac conduction subpanel – $1000
- Cardiomyopathy gene subpanel -$1000
- Marfan Syndrome subpanel – $1600
- Rasopathy Subpanel – $1000
Other Genetic Testing
- 5alpha-Reductase – $600
- Achondroplasia (Short Stature) – $800
- Acyl-Coenzyme A Dehydrogenase – $500
- ACADM – $200
- Alagille Syndrome – $1300
- Alexander Disease – $800
- Alpers Syndrome – $600
- Alpha-Thalassemia X-Linked Intellectual Disability – $1000
- Androgen Receptor – $1000
- Angelman Syndrome – $400
- Ataxia 66 genes – $1100
- Axenfeld-Rieger Syndrome – $400
- Becker Muscular Dystrophy – $600
- DMD (cDNA-Frozen Muscle) – $2000
- Beckwith Wiedemann Syndrome – $400
- Blepharophimosis-Ptosis-Epicanthus (BPES) – $600
- CADASIL NOTCH3 $1100
- Cerebral Cavernous Malformation – $1900
- Charcot-Marie-Tooth Neuropathy – $1100
- CHARGE Syndrome – $1600
- Congenital Adrenal Hyperplasia – $900
- Congenital Muscular Dystrophy – $1100
- Congenital Myasthenic Syndrome – $1100
- Cri du Chat Syndrome – $300
- Cystic Fibrosis (CF) – $200
- Deafness / Connexin (CX) – $300
- Deafness / Aminoglycoside Hearing Loss – $200
- Dentatorubral-Pallidoluysian Atrophy – $200
- DiGeorge Syndrome (DGS) – $300
- Distal Arthrogryposis (DA2B) – $1100
- Duchenne Muscular Dystrophy – $600
- DMD (cDNA) Frozen Muscle – $2000
- Dystonia TOR1A (Common Mutation) – $200
- Familial Cerebral Angiopathy – $200
- Familial Visceral Myopathy / Berdon Syndrome – $900
- Friedreich Ataxia – $300
- Glycogen Storage Disease/Rhabdomyolysis – $1100
- Haemophilia A Factor VIII – $500
- Hereditary Pancreatitis (PCTT) – $600
- Hereditary Spastic Paraparesis – $1100
- Hypokalemic Periodic Paralysis – $400
- Hypothyroidism – $2000
- Incontinentia Pigmenti / Bloch-Sulzberger Syndrome – $1000
- Kallmann Syndrome – $1900
- Kearns-Sayre Syndrome (KSS) – $1000
- Kennedy Disease – $200
- Langer-Giedion Syndrome (LGS) – $300
- Leber Hereditary Optic Neuropathy (LHON) – $600
- Leukodystrophy – $1100
- Lissencephaly /Microcephaly – $1100
- Lymphedema-Distichiasis Syndrome – $500
- Malignant Hyperthermia (MH) – $2000
- Maternally-Inherited Leigh Syndrome (MILS) – $300
- McArdle Disease (GSDV) – $200
- MELAS MT-TL1 (Common Mutation) – $300
- Melnick-Needles Syndrome (MNS) – $1300
- MERRF MT-TK (Common Mutation) – $300
- Microdeletion of the Y Chromosome AZF (Males Only) – $200
- Microdeletions – $300
- Miller-Dieker Syndrome (MDS) – $300
- Mitochondrial Myopathy (Nuclear) – $1100
- Motor Neurone Disease/Spinal Muscular Atrophy – $1100
- Moyamoya Disease (MYMY) – $900
- Myotonic Dystrophy (DM) – $400
- Myopathy – $1100
- Muscle Channelopathy – $1100
- Nemaline Myopathy (NEM) – $200
- Neurogenic Ataxia w Retinitis Pigmentosa – $300
- Oculocutaneous Albinism (OCA) TYR (Type 1-) $800
- Oculopharyngeal Muscular Dystrophy (OPMD) – $200
- Phelan-McDermid Syndrome (PMS) – $300
- Potocki-Lupski Syndrome (PTLS) – $300
- Prader-Willi Syndrome (PWS) – $400
- Prion Disease (TSE) – $300
- Progressive External Ophthalmoplegia (CPEO) – $1000
- Rett Syndrome (RTT) – $300
- Rippling Muscle Disease (RMD) – $300
- Rubinstein-Taybi Syndrome (RSTS) – $300
- Russell Silver Syndrome (RSS) – $400
- Shwachman-Diamond Syndrome (SDS) – $1000
- Simpson-Golabi-Behmel Syndrome – $300
- Smith-Magenis Syndrome (SMS) – $300
- SOTOS Syndrome – $1000
- Spinal Muscular Atrophy (SMA) – $300
- Spinocerebellar Ataxia (SCA) – $200
- Tauopathies MAPT – $600
- Uniparental Disomy (UPD) – $400
- WAGR Syndrome – $300
- Williams-Beuren Syndrome (WBS) – $300
- Wilson Disease (WND) – $1300
- Wiskott-Aldrich Syndrome (WAS) – $1300
- Wolf-Hirschhorn Syndrome (WHS) – $300
- X Inactivation Studies (AR) – $400
- X-Linked Agammaglobulinemia – $1500
- X-Linked Anhidrotic Ectodermal Dysplasia – $1600
- X-Linked Hydrocephalus (HYCX) – $1300
- X-Linked Mental Retardation (MRX) – $1000