■ site map
BLOG: November 2007
Imprinted genesAre you having imprinted genes, and why should you worry? Genetic research is beginning to unravel the mysterious inner workings of human genes, and at least partial answers are beginning to surface. Recently, as reported by Associated Press, Duke University scientists have created first map of imprinted genes, expanding their number from 40 to nearly 200. These genes are linked to some major diseases, like obesity, cancer and diabetes.
First off - what is imprinted gene? As you may know, each of us inherits a double set of genes, one from each parent. The second copy is dormant, and serves as a sort of safety backup: if a gene from the functioning copy for any reason stops working, your spare gene often kicks in to replace it.
The problem is, this backup gene sometimes comes with what in translation from molecular language would read "Do not activate" code, or imprint. In other words, imprinted, or silenced genes are those that simply stay inactive.
Obviously, having a single working gene instead of a set of two makes you more vulnerable to any health effects coming from that gene, too, being silenced or damaged later in your life.
Genetic imprint is different than either not having particular genes - which also can be inherited - or having particular genes altered or damaged. It is very similar to epigenetic damage, where the gene itself is intact, but something in the set of external (to the gene) factors necessary to complete the chain of reactions leading to the production of gene-specific body proteins - so called gene expression - is altered, preventing this from happening.
Imprinted genes themselves can come from three different sources. One is when they are directly inherited as silenced genes from a parent. Obviously, there is a possibility that both parents have identical genes silenced, in which case any related health effects show immediately.
The second possibility of acquiring imprinted genes is during developmental phase, particularly in mother's womb, when the DNA (and the body in general) is most sensitive to the effects of external factors, such as oral intake (food, drinks, drugs), chemicals, stress, or other interactions with the living environment.
The third is having them silenced later in life, mainly as a consequence of genetic errors/damage accumulated during many cellular divisions throughout the lifetime (genetic damage by toxin damage is also possible).
Depending on how numerous is your set of functional genes in the beginning, you will be more - or less - vulnerable to both, effects of gene silencing in your adult life, and genetic damage by a number of gene-unfriendly factors you may be exposed to.
The good news about imprinted genes is that the "stay silent" imprint
can be erased.
It has been done, already, by epigenetic therapy. At present for a limited number of diseases (MDS, or Myelodysplastic Syndrome, some solid malignant tumors, bipolar disorder), but is expected to expand as scientists figure out how to work with other types of genes.