- Acute Flaccid Myelitis
- Alzheimer’s Disease
- Arteriovenous Malformations
- Attention Deficit Hyperactivity Disorder
- Back Pain
- Brain Aneurysm
- Brain Tumors
- Carpal Tunnel Syndrome
- Childhood Brain Tumors
- Delirium
- Dementia
- Hemorrhagic Stroke
- Ischemic Stroke
- Memory
- Meningitis
- Mild Cognitive Impairment
- Movement Disorders
- Multiple Sclerosis
- Neuroblastoma
- Neuromuscular Disorders
- Parkinson’s Disease
- Polio and Post-Polio Syndrome
- Speech and Language Problems in Children
- Stroke
- Transient Ischemic Attack
- Tremor
- Walking Problems
- West Nile Virus
- A1C
- Blood Glucose
- Diabetes
- Diabetes and Pregnancy
- Diabetes Complications
- Diabetes in Children and Teens
- Diabetes Medicines
- Diabetes Type 1
- Diabetes Type 2
- Diabetic Diet
- Diabetic Eye Problems
- Diabetic Foot
- Diabetic Heart Disease
- Diabetic Kidney Problems
- Diabetic Nerve Problems
- How to Prevent Diabetes
- Hyperglycemia
- Metabolic Syndrome
- Prediabetes
- Abortion
- Breast Cancer
- Breast Diseases
- Breast Reconstruction
- Breastfeeding
- Cervical Cancer
- Cervical Cancer Screening
- Cesarean Delivery
- Childbirth
- Ectopic Pregnancy
- Endometriosis
- Female Infertility
- Health Problems in Pregnancy
- High Blood Pressure in Pregnancy
- HIV and Pregnancy
- Hormone Replacement Therapy
- HPV
- Hysterectomy
- Infections and Pregnancy
- Mammography
- Mastectomy
- Menopause
- Menstruation
- Miscarriage
- Ovarian Cancer
- Ovarian Cysts
- Ovarian Disorders
- Pelvic Floor Disorders
- Pelvic Inflammatory Disease
- Pelvic Pain
- Period Pain
- Polycystic Ovary Syndrome
- Pregnancy
- Pregnancy and Drug Use
- Pregnancy and Opioids
- Premenstrual Syndrome
- Prenatal Care
- Prenatal Testing
- Primary Ovarian Insufficiency
- Sexual Problems in Women
- Stillbirth
- Teenage Pregnancy
- Trichomoniasis
- Tubal Ligation
- Uterine Cancer
- Uterine Diseases
- Uterine Fibroids
- Vaginal Bleeding
- Vaginal Cancer
- Vaginal Diseases
- Vaginitis
- Vulvar Cancer
- Vulvar Disorders
- Yeast Infections
- Alcohol
- Calcium
- Child Nutrition
- Cholesterol
- Cholesterol Levels: What You Need to Know
- Cholesterol Medicines
- DASH Eating Plan
- Eating Disorders
- Food Allergy
- HDL: The “Good” Cholesterol
- High Cholesterol in Children and Teens
- How to Lower Cholesterol
- How to Lower Cholesterol with Diet
- Infant and Newborn Nutrition
- LDL: The “Bad” Cholesterol
- Malabsorption Syndromes
- Nutrition for Older Adults
- Pregnancy and Nutrition
- Toddler Nutrition
- Triglycerides
- VLDL Cholesterol
- Alpha-1 Antitrypsin Deficiency
- Ataxia Telangiectasia
- Brain Malformations
- Cerebral Palsy
- Charcot-Marie-Tooth Disease
- Chiari Malformation
- Cleft Lip and Palate
- Color Blindness
- Congenital Heart Defects
- Craniofacial Abnormalities
- Cystic Fibrosis
- Ehlers-Danlos Syndrome
- Fetal Alcohol Spectrum Disorders
- Friedreich Ataxia
- Genetic Counseling
- Hemophilia
- Huntington’s Disease
- Hydrocephalus
- Muscular Dystrophy
- Neural Tube Defects
- Neurofibromatosis
- Newborn Screening
- Osteogenesis Imperfecta
- Prader-Willi Syndrome
- Pregnancy and Medicines
- Rett Syndrome
- Sickle Cell Disease
- Spina Bifida
- Spinal Muscular Atrophy
- Tay-Sachs Disease
- Tourette Syndrome
- Tuberous Sclerosis
- Usher Syndrome
- Acute Lymphocytic Leukemia
- Allergy
- Animal Bites
- Ankylosing Spondylitis
- Aplastic Anemia
- Asthma
- Asthma in Children
- Childhood Leukemia
- Childhood Vaccines
- Chronic Lymphocytic Leukemia
- COVID-19 Vaccines
- Cryptosporidiosis
- Eosinophilic Disorders
- Eosinophilic Esophagitis
- Giant Cell Arteritis
- Hay Fever
- HIV
- HIV and Infections
- HIV in Women
- Hodgkin Lymphoma
- Infectious Diseases
- Infectious Mononucleosis
- Juvenile Arthritis
- Kawasaki Disease
- Lymphedema
- Lymphoma
- Multiple Myeloma
- Pemphigus
- Pneumocystis Infections
- Rheumatoid Arthritis
- Scleroderma
- Sjogren’s Syndrome
- Tonsillitis
- Vaccines
- Viral Infections
- Adhesions
- Ankle Injuries and Disorders
- Arm Injuries and Disorders
- Back Injuries
- Brachial Plexus Injuries
- Burns
- Chest Injuries and Disorders
- Concussion
- CPR
- Dislocated Shoulder
- Dislocations
- Elbow Injuries and Disorders
- Eye Injuries
- Facial Injuries and Disorders
- Finger Injuries and Disorders
- Foot Injuries and Disorders
- Fractures
- Hand Injuries and Disorders
- Heel Injuries and Disorders
- Hip Injuries and Disorders
- Inhalation Injuries
- Insect Bites and Stings
- Jaw Injuries and Disorders
- Knee Injuries and Disorders
- Leg Injuries and Disorders
- Mosquito Bites
- Neck Injuries and Disorders
- Rotator Cuff Injuries
- Shoulder Injuries and Disorders
- Spinal Cord Injuries
- Sprains and Strains
- Tick Bites
- Toe Injuries and Disorders
- Traumatic Brain Injury
- Wrist Injuries and Disorders
- Acute Bronchitis
- Bird Flu
- Chronic Bronchitis
- COPD
- COVID-19 (Coronavirus Disease 2019)
- Croup
- E-Cigarettes
- Fistulas
- Flu
- Granulomatosis with Polyangiitis
- H1N1 Flu (Swine Flu)
- Legionnaires’ Disease
- Lung Cancer
- Mesothelioma
- Pneumonia
- Pulmonary Hypertension
- Respiratory Syncytial Virus Infections
- Sleep Apnea
- Smoking
- Tuberculosis
- Whooping Cough
- Anatomy
- Assisted Reproductive Technology
- Birth Control
- Chlamydia Infections
- Circumcision
- Erectile Dysfunction
- Genital Herpes
- Genital Warts
- Gonorrhea
- Herpes Simplex
- Infertility
- Male Infertility
- Penis Disorders
- Prostate Cancer
- Prostate Cancer Screening
- Prostate Diseases
- Reproductive Hazards
- Sexual Health
- Sexual Problems in Men
- Sexually Transmitted Diseases
- Syphilis
- Testicular Cancer
- Testicular Disorders
- Vasectomy
- Abdominal Pain
- Bad Breath
- Bleeding
- Breathing Problems
- Bruises
- Chest Pain
- Choking
- Chronic Pain
- Constipation
- Cough
- Diarrhea
- Dizziness and Vertigo
- Edema
- Fainting
- Fever
- Frostbite
- Gas
- Gastrointestinal Bleeding
- Headache
- Heartburn
- Heat Illness
- Hives
- Hypothermia
- Indigestion
- Itching
- Jaundice
- Nausea and Vomiting
- Pain
- Rare Diseases
- Raynaud’s Disease
- Sciatica
- Speech and Communication Disorders
- Stuttering
Genetic Testing
Summary
What is genetic testing?
Genetic testing is a type of medical test that looks for changes in your DNA. DNA is short for deoxyribonucleic acid. It contains the genetic instructions in all living things. Genetic tests analyze your cells or tissue to look for any changes in:
- Genes, which are parts of DNA that carry the information needed to make a protein
- Chromosomes, which are thread-like structures in your cells. They contain DNA and proteins.
- Proteins, which do most of the work in your cells. Testing can look for changes in the amount and activity level of proteins. If it finds changes, it might be due to changes in your DNA.
Why is genetic testing done?
Genetic testing may be done for many different reasons, including to:
- Find genetic diseases in unborn babies. This is one type of prenatal testing.
- Screen newborn babies for certain treatable conditions
- Lower the risk of genetic diseases in embryos that were created using assisted reproductive technology
- Find out if you carry a gene for a certain disease that could be passed on to your children. This is called carrier testing.
- See whether you are at increased risk of developing a specific disease. This may be done for a disease that runs in your family.
- Diagnose certain diseases
- Identify genetic changes that may be causing or contributing to a disease that you were already diagnosed with
- Figure out how severe a disease is
- Help guide your doctor in deciding the best medicine and dosage for you. This is called pharmacogenomic testing.
How is genetic testing done?
Genetic tests are often done on a blood or cheek swab sample. But they may also be done on samples of hair, saliva, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. The sample is sent to a laboratory. There, a lab technician will use one of several different techniques to look for genetic changes.
What are the benefits of genetic testing?
The benefits of genetic testing include:
- Helping doctors make recommendations for treatment or monitoring
- Giving you more information for making decisions about your health and your family’s health:
- If you find out that you are at risk for a certain disease, you might take steps to lower that risk. For example, you may find out that you should be screened for a disease earlier and more often. Or you might decide to make healthy lifestyle changes.
- If you find out that you are not at risk for a certain disease, then you can skip unnecessary checkups or screenings
- A test could give you information that helps you make decisions about having children
- Identifying genetic disorders early in life so treatment can be started as soon as possible
What are the drawbacks of genetic testing?
The physical risks of the different types of genetic testing are small. But there can be emotional, social, or financial drawbacks:
- Depending on the results, you may feel angry, depressed, anxious, or guilty. This can be especially true if you are diagnosed with a disease that does not have effective treatments.
- You may be worried about genetic discrimination in employment or insurance
- Genetic testing may give you limited information about a genetic disease. For example, it cannot tell you whether you will have symptoms, how severe a disease might be, or whether a disease will get worse over time.
- Some genetic tests are expensive, and health insurance might only cover part of the cost. Or they may not cover it at all.
How do I decide whether to be tested?
The decision about whether to have genetic testing is complex. In addition to discussing the test with your health care provider, you can meet with a genetic counselor. Genetic counselors have specialized degrees and experience in genetics and counseling. They can help you understand the tests and weigh the risks and benefits. If you do get a test, they can explain the results and make sure that you have the support that you need.
National Human Genome Research Institute
Related Issues
- At-Home Medical Tests National Library of Medicine
- Genetics National Institute of General Medical Sciences
- Genetics: MedlinePlus Genetics National Library of Medicine
- Genomic Testing Centers for Disease Control and Prevention
- How can consumers be sure a genetic test is valid and useful?: MedlinePlus Genetics National Library of Medicine
- How is genetic testing done?: MedlinePlus Genetics National Library of Medicine
- What are the risks and limitations of genetic testing?: MedlinePlus Genetics National Library of Medicine
- What do the results of genetic tests mean?: MedlinePlus Genetics National Library of Medicine
- What Is a Pediatric Geneticist? American Academy of Pediatrics
- What is direct-to-consumer genetic testing?: MedlinePlus Genetics National Library of Medicine
Specifics
- BRCA Gene Mutations: Cancer Risk and Genetic Testing National Cancer Institute
- BRCA Test National Library of Medicine
- Carrier Screening American College of Obstetricians and Gynecologists
- Genetic Testing for Hereditary Cancer Susceptibility Syndromes National Cancer Institute
- Genetic Testing for Inherited Heart Disease American Heart Association
- Have You or a Family Member Had Colon Cancer? Centers for Disease Control and Prevention
- Karyotype Genetic Test National Library of Medicine
- MTHFR Mutation Test National Library of Medicine
- Pharmacogenetic Tests National Library of Medicine
- PTEN Genetic Test National Library of Medicine
- TP53 Genetic Test National Library of Medicine
- What are the types of genetic tests?: MedlinePlus Genetics National Library of Medicine
- What is genetic ancestry testing?: MedlinePlus Genetics National Library of Medicine
Patient Handouts
- BRCA1 and BRCA2 gene testing Medical Encyclopedia
- Genetic testing and your cancer risk Medical Encyclopedia
Encyclopedia
- Buccal smear Medical Encyclopedia
- Karyotyping Medical Encyclopedia
Find an Expert
- Centers for Disease Control and Prevention Centers for Disease Control and Prevention
- Genetic Alliance Genetic Alliance
- Genetic and Rare Diseases Information Center Genetic and Rare Diseases Information Center
- National Human Genome Research Institute National Human Genome Research Institute
Clinical Trials
- ClinicalTrials.gov: Genetic Testing National Institutes of Health
NIH MedlinePlus Magazine
- Diagnosis of Lynch Syndrome: Genetic Testing Identifies a Potentially Deadly Hereditary Disease
- Is Genetic Testing Right for You?
- Missing Ancestry: Filling in a Genetic Background
- Precision Environmental Health’s Role in Preventing Disease
Start Here
- Frequently Asked Questions about Genetic Testing National Human Genome Research Institute
- Genetic Testing (For Parents) Nemours Foundation
- Genetic Testing: What You Should Know American Academy of Family Physicians
- Regulation of Genetic Tests National Human Genome Research Institute
Reference Desk
- GeneReviews Glossary National Center for Biotechnology Information
- Genetic Testing Registry National Center for Biotechnology Information
- Genomics and Precision Health Weekly Update Centers for Disease Control and Prevention
- Talking Glossary of Genetic Terms National Human Genome Research Institute
Statistics and Research
- Genetic Mapping National Human Genome Research Institute
Videos and Tutorials
- Genetic Testing College of American Pathologists