What do dna tests show

However, women interested in this type of genetic testing sometimes recruit a male relative to have the test done. Because the Y chromosome is passed on in the same pattern as are family names in many cultures, Y chromosome testing is often used to investigate questions such as whether two families with the same surname are related.

This type of testing identifies genetic variations in mitochondrial DNA. Although most DNA is packaged in chromosomes within the cell nucleus, cell structures called mitochondria also have a small amount of their own DNA known as mitochondrial DNA.

Both males and females have mitochondrial DNA, which is passed on from their mothers, so this type of testing can be used by either sex. It provides information about the direct female ancestral line. Mitochondrial DNA testing can be useful for genealogy because it preserves information about female ancestors that may be lost from the historical record because of the way surnames are often passed down.

The results are compared with those of others who have taken the tests to provide an estimate of a person's ethnic background. For example, the pattern of SNPs might indicate that a person's ancestry is approximately 50 percent African, 25 percent European, 20 percent Asian, and 5 percent unknown. Genealogists use this type of test because Y chromosome and mitochondrial DNA test results, which represent only single ancestral lines, do not capture the overall ethnic background of an individual.

This is especially useful for conditions like familial hyperlipidemia, which can result in premature heart attacks and stroke.

Catching these types of diseases during their early stages as in, before a first heart attack means a patient will possibly have more options for treating the disease. This type of testing is usually only done in a health-care setting. When a healthy person with no symptoms has a documented family history of a disease, such as diabetes , genetic tests can analyze specific markers in their genes that are related to that disease, said Feero.

Doctors may then use this information to predict whether that person is at risk of developing the condition. In the case of Huntington's disease, that mutation is an expansion of the region of DNA in a particular gene. But when it comes to diseases that involve multiple mutations, occurring in one or a few genes, determining a person's risk is a little more complex, said Feero. Some conditions aren't just caused by changes in a single gene, but rather, a whole range of changes across, potentially, multiple genes.

Feero said genetic testing can be useful by allowing doctors to analyze the different types of gene changes. This can give them an idea of whether someone will get a disease, how bad it will be, and perhaps insights on potential treatments. Genetic testing can help with family planning. Sometimes people who are totally healthy can have mutations in their DNA that are associated with different genetic disorders, explained Feero.

This is called being a carrier, and it basically means their DNA inherited a single copy of the gene mutation for that hereditary condition or disease. Generally, the condition doesn't actually affect that person or their health , because their DNA still has an additional copy of that same gene that doesn't have the mutation.

For example, if you're a carrier for a disease mutation linked to cystic fibrosis, it doesn't mean you have cystic fibrosis. However, when two future parents turn out to be carriers for the same genetic disorder, their child may develop the disease, explained Feero. He told INSIDER, "If a woman is a carrier of a mutation for cystic fibrosis, and her partner is also a carrier of a mutation in one of his cystic fibrosis genes, their baby has a one in four chance of inheriting two bad copies of those genes.

Expanded carrier status screening is a type of genetic DNA test that can estimate reproductive risks in healthy individuals, said Feero. He told INSIDER, "Expanded carrier status screening can be useful if you are a woman who is contemplating pregnancy, and you want to know what genetic changes you might have in your DNA that could predict risk for multiple relatively rare, serious diseases in your newborn. For example, [certain] changes in your DNA might be associated with cystic fibrosis or Tay-Sachs risk for the baby.

Today, many fertility clinics and other health-care facilities offer tests that can tell you if you are a carrier for different genetic disorders. There are also several direct-to-consumer DNA tests that provide these types of results, too. The other issue is for those folks who took DNA tests and got back results they didn't expect.

There are many issues involved with this, from what's called " misattributed paternity " to issues of race , what you've been told as part of your family history, and disturbing discoveries about your family tree. In it, we looked at how well these providers can help you learn about yourself through DNA.

Each provider is shown with the size of its matching database. If you're looking for family information, the bigger the database, the better the chance you'll find long-lost family members. When it comes to health and lifestyle information, the DNA tests use some of the same information.

This is really a matching process, but instead of looking for family members, the test provider looks for matching characteristics, particularly genetic markers for certain diseases and traits. Coronavirus: Business and technology in a pandemic. From cancelled conferences to disrupted supply chains, not a corner of the global economy is immune to the spread of COVID DNA, is essentially, code.

The order and combination of the code provide instructions for creating organic material. Segments of DNA convert amino acids into proteins. Proteins do all sorts of things, including create new cells. That's how you get the building blocks, from amino acids to proteins, proteins to cells, cells to tissues, tissues to organs, and organs to people, dogs, trees, cats, and so on.

Long strands of DNA are called chromosomes. These chromosomes are passed from both a father and a mother to a child. The child's DNA contains code that represents characteristics of both parents.

These chromosomes not only contain code for genetic characteristics, they also contain something of a genetic fingerprint of the parents in each child. That's why two siblings, born of the same two parents, will share a considerable amount of chromosomal data.

Cousins, too, share chromosomal data, just not as much. The fingerprint has, essentially, been diluted. As you move back in time to grandparents and great grandparents and great great grandparents, and then down other branches of the tree to first cousins, second cousins, third cousins, fourth cousins, and so forth, less and less of the DNA sequences will match.

The reason you need to understand a bit about chromosomes is that you're about to make a decision: Which test type do you choose? That's next. Genetic testing is voluntary. Because testing has benefits as well as limitations and risks , the decision about whether to be tested is a personal and complex one. A geneticist or genetic counselor can help by providing information about the pros and cons of the test and discussing the social and emotional aspects of testing.

Other chapters in Help Me Understand Genetics. Genetics Home Reference has merged with MedlinePlus. Learn more. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.