Rich DNA Diversity
In the past two decades we have witnessed a genetic revolution, along the way, we have discovered how genetically similar we are to each other. Technology deciphered astonishing biochemical variations that make every one of us unique.
The Basics
A series of chemical procedures break down cells in the saliva. On occasion saliva contains cells from the inside of the cheek or cells from the glands. You just have to crack open the chromosomes, then you centrifuge it and use various techniques to separate the DNA itself.
The precise DNA segment being examined by the chip is flagged by a chemical process, usually through a fluorescent dye to mark different locations and segments. We call this chip genotyping or microarray genotyping, and it gives you, depending on the chip, somewhere from several hundreds of thousands to the order of a million markers all along the person’s DNA.
Ethnicity estimates; One of the things done is using large data sets to mathematically analyze the probability that someone can be linked to a specific ethnic group or is a mix of various ancestry groups, called haplogroups. All companies get information from, depend on, and use public ancestry data sets such as the International HapMap Project and the Human Genome Diversity Project. This is what causes dissimilarities in ethnicity percentages when DNA samples are provided to different companies.
At the intersection
Most consumer genetic testing companies amass data on thousands of genetic variations that may have an influence on health.
Changes to the DNA structure can be small, like single nucleotide polymorphisms (SNPs), where a single letter is changed to a different letter. Or they can be a lot bigger where many DNA letters are added, deleted or rearranged. Genetic variation can alter how a drug is metabolized. If a drug is metabolized too quickly, it might not be as effective. Alternatively, if the drug is metabolized too slowly, it may build up in the body and cause dangerous side effects.
CYP2D6 Gene localizes to the endoplasmic reticulum and is known to metabolize as many as 25% of commonly prescribed drugs, like antidepressants, antipsychotics, analgesics & others.
For example, it converts the painkiller codeine into its active form, morphine. There are more than 160 versions of the CYP2D6 gene. Many vary by only a single difference in their DNA sequence. Others have larger changes. Most of these variants don’t affect how people respond to the drug.
Typically, people have two copies of each gene. However, some people have hundreds or even thousands of copies of the CYP2D6 gene. Those with extra copies produce too much of the CYP2D6 enzyme and process the drug very fast. As a result, their bodies may convert codeine to morphine so quickly and completely that a standard dose can be an overdose. In contrast, some variants of CYP2D6 create an enzyme that doesn’t work. People with these variants process codeine slowly, if at all, leading to little, if any, pain relief. For them, doctors can prescribe a different drug.
In the mid 1970s the FDA approved the first home pregnancy test. An article in The American Journal of Public Health in 1976, argued to limit the use of such potentially dangerous kits.
At the junction of recreational genetic genealogy and personal health information. I do believe that people have the right for this information, but also take on an additional responsibility to be responsible & not simply foster misinterpretation, because DNA results are fascinating world. Whether you’re talking about ancestry or medical genetics, it’s not instinctively straightforward all the time.
Happy Exploring!
