What is a Cell?

Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. ... read more »

What is DNA?

DNA, or deoxyribonucleic acid, is the hereditary material in humans andalmost all other organisms. Nearly every cell in a person's body has the same DNA. Most DNA is located in the cell nucleus (where it is callednuclear DNA). ... read more »

Do All Gene Mutations Affect Health and Development?

No; only a small percentage of mutations cause genetic disorders'mosthave no impact on health or development. For example, some mutationsalter a gene's DNA sequence but do not change the function of theprotein made by the gene. ... read more »

What is Genetic Testing?

Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. ... read more »

What are Complex or Multifactorial Disorders?

Researchers are learning that nearly all conditions and diseases have a genetic component. Some disorders, such as sickle cell anemia and cystic fibrosis, are caused by mutations in a single gene. ... read more »

How is Genetic Testing Done?

Once a person decides to proceed with genetic testing, a medical geneticist, primary care doctor, specialist, or nurse practitioner can order the test. Genetic testing is often done as part of a genetic consultation. ... read more »

How are Genetic Conditions and Genes Named?

Genetic conditions are not named in one standard way (unlike genes, which are given an official name and symbol by a formal committee). Doctors who treat families with a particular disorder are often the first to propose a name for the condition. ... read more »

What is Direct-to-Consumer Genetic Testing?

Traditionally, genetic tests have been available only through healthcare providers such as physicians, nurse practitioners, and genetic counselors. ... read more »

Why is it Important to Know My Family Medical History?

A family medical history is a record of health information about a person and his or her close relatives. A complete record includes information from three generations of relatives. ... read more »

How Can Consumers be Sure a Genetic Test is Valid and Useful?

Before undergoing genetic testing, it is important to be sure that the test is valid and useful. A genetic test is valid if it provides an accurate result. Two main measures of accuracy apply to genetic tests: analytical validity and clinical validity. ... read more »

What do the Results of Genetic Tests Mean?

The results of genetic tests are not always straightforward, which often makes them challenging to interpret and explain. ... read more »

What are Reduced Penetrance and Variable Expressivity?

Reduced penetrance and variable expressivity are factors that influence the effects of particular genetic changes. These factors usually affect disorders that have an autosomal dominant pattern of inheritance. ... read more »

Will Health Insurance Cover the Costs of Genetic Testing?

In many cases, health insurance plans will cover the costs ofgenetic testing when it is recommended by a person's doctor. Healthinsurance providers have different policies about which tests arecovered, however. ... read more »

What do Geneticists Mean by Anticipation?

The signs and symptoms of some genetic conditions tend to become more severe and appear at an earlier age as the disorder is passed from one generation to the next. This phenomenon is called anticipation. ... read more »

What are Genomic Imprinting and Uniparental Disomy?

Genomic imprinting and uniparental disomy are factors that influence how some genetic conditions are inherited. ... read more »

What is a Genetic Consultation?

A genetic consultation is a health service that provides information and support to people who have, or may be at risk for, genetic disorders. ... read more »

Why Might Someone Have a Genetic Consultation?

Individuals or families who are concerned about an inherited condition may benefit from a genetic consultation. The reasons that a person might be referred to a genetic counselor, medical geneticist, or other genetics professional include: ... read more »

What Kinds of Gene Mutations are Possible?

The DNA sequence of a gene can be altered in a number of ways. Gene mutations have varying effects on health, depending on where they occur and whether they alter the function of essential proteins. ... read more »

What Happens During a Genetic Consultation?

A genetic consultation provides information, offers support, andaddresses a patient's specific questions and concerns. To help determine whether a condition has a genetic component, a genetics professionalasks about a person's medical history. ... read more »

How Can I Find a Genetics Professional in My Area?

To find a genetics professional in your community, you may wish to ask your doctor for a referral. If you have health insurance, you can also contact your insurance company to find a medical geneticist or genetic counselor in your area who participates in your plan. ... read more »

How are Genetic Conditions Diagnosed?

A doctor may suspect a diagnosis of a genetic condition on the basis of a person's physical characteristics and family history, or on theresults of a screening test. ... read more »

How are Genetic Conditions Treated or Managed?

Many genetic disorders result from gene changes that are present in essentially every cell in the body. As a result, these disorders often affect many body systems, and most cannot be cured. ... read more »

Is Gene Therapy Available to Treat My Disorder?

Gene therapy is currently available only in a research setting. The U.S. Food and Drug Administration (FDA) has not yet approved any gene therapy products for sale in the United States. ... read more »

What is a Genome?

A genome is an organism's complete set of DNA, including all of itsgenes. Each genome contains all of the information needed to build andmaintain that organism. ... read more »

What Were the Goals of the Human Genome Project?

The main goals of the Human Genome Project were to provide a complete and accurate sequence of the 3 billion DNA base pairs that make up the human genome and to find all of the estimated 20,000 to 25,000 human genes. ... read more »

What Did the Human Genome Project Accomplish?

In April 2003, researchers announced that the Human Genome Project had completed a high-quality sequence of essentially the entire human genome. This sequence closed the gaps from a working draft of the genome, which was published in 2001. ... read more »

What are the Next Steps in Genomic Research?

Discovering the sequence of the human genome was only the first step in understanding how the instructions coded in DNA lead to a functioning human being. The next stage of genomic research will begin to derive meaningful knowledge from the DNA sequence. ... read more »

Gene Therapy

Gene Therapy ... read more »

What are Single Nucleotide Polymorphisms (SNPs)?

Single nucleotide polymorphisms, frequently called SNPs (pronounced'snips'), are the most common type of genetic variation among people.Each SNP represents a difference in a single DNA building block, called a nucleotide. ... read more »

The Human Genome Project

The Human Genome Project ... read more »

What are the Benefits of Genetic Testing?

Genetic testing has potential benefits whether the results are positive or negative for a gene mutation. Test results can provide a sense of relief from uncertainty and help people make informed decisions about managing their health care. ... read more »

What are Genome-wide Association Studies?

Genome-wide association studies are a relatively new way for scientists to identify genes involved in human disease. ... read more »

What are the Risks and Limitations of Genetic Testing?

The physical risks associated with most genetic tests are very small, particularly for those tests that require only a blood sample or buccal smear (a procedure that samples cells from the inside surface of the cheek). ... read more »

What is the International HapMap Project?

The International HapMap Project is an international scientific effort to identify common genetic variations among people. This project represents a collaboration of scientists from public and private organizations in six countries. ... read more »

What is the Encyclopedia of DNA Elements (ENCODE) Project?

The ENCODE Project was planned as a follow-up to the Human Genome Project. The Human Genome Project sequenced the DNA that makes up the human genome; the ENCODE Project seeks to interpret this sequence. ... read more »

What is Genetic Discrimination?

Genetic discrimination occurs when people are treated differently by their employer or insurance company because they have a gene mutation that causes or increases the risk of an inherited disorder. ... read more »

What is Genetic Ancestry Testing?

Genetic ancestry testing, or genetic genealogy, is a way for people interested in family history (genealogy) to go beyond what they can learn from relatives or from historical documentation. ... read more »

What Advances are Being Made in DNA Sequencing?

Determining the order of DNA building blocks (nucleotides) in anindividual's genetic code, called DNA sequencing, has advanced the study of genetics and is one method used to test for genetic disorders. ... read more »

How Does Gene Therapy Work?

Gene therapy is designed to introduce genetic material into cells to compensate for abnormal genes or to make a beneficial protein. ... read more »

Is Gene Therapy Safe?

Gene therapy is under study to determine whether it could be used to treat disease. Current research is evaluating the safety of gene therapy; future studies will test whether it is an effective treatment option. ... read more »

What are the Ethical Issues Surrounding Gene Therapy?

Because gene therapy involves making changes to the body's set of basicinstructions, it raises many unique ethical concerns. ... read more »

Mitochondrial Diseases in Children a Thing of the Past?

Researchers from the NYSCF (New York Stem Cell Foundation) partnered with CUMC (Columbia Medical Center) to create a special technique to stop mitochondrial diseases from genetically passing on to children. The technique is in the earliest clinical stages. ... read more »

Aniridia

Aniridia is a congenital eye disorder also referred to as iris hypoplasia. At first glance, patients with aniridia appear to have no iris (colored part of the eye), but a closer look reveals the root of the iris. ... read more »

Chromosomal Testing on IVF Embryos - Should You Do It?

Chromosomal testing on IVF embryos is not usually a regular part of the IVF process. However, some fertility specialists are offering it to couples who hope to use it to increase their chances of transferring a healthy, strong embryo to the woman's uterus. ... read more »

PKU – Phenylketonuria

Phenylketonuria or PKU is a genetic condition preventing the body from breaking down the amino acid phenylalanine and two similar substances commonly found in protein. PKU causes a build-up of the amino acid, which can lead to developmental delay. ... read more »

FDA Says Stop Selling 23andMe DNA Tests

More than half a million customers have had their blood tested but the US Food and Drug Administration (FDA) says enough already. The federal agency governing medical devices has recently issued a warning letter to the product's manufacturer. ... read more »

What Would You Do If Genetic Testing Revealed Future Illness?

What would you do if genetic testing revealed future catastrophic illness for yourself or a child? Would you want to know? ... read more »

What are the Types of Genetic Tests?

Genetic testing can provide information about a person's genes and chromosomes. ... read more »

What is Pharmacogenomics?

This relatively new field combines pharmacology (the science of drugs)and genomics (the study of genes and their functions) to developeffective, safe medications and doses that will be tailored to aperson's genetic makeup. ... read more »

Heterochromia and Pregnancy

Heterochromia is a genetic or acquired eye condition that affects the iris. There are three forms of the condition: complete, sectoral and central. ... read more »

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