Being predisposed towards certain ailments or medical conditions, based on a DNA test, do not necessarily mean a person has or his or her future offspring would have the same disease or condition. That, in essence, is the main message of a new book titled “Genomic Messages.”

Authored by lawyer George Annas and geneticist Sherman Elias, the book warns of the danger in overusing and overtrusting the knowledge gained from genomics.

The landmark Human Genome Project in 2003 mapped every gene of every chromosome in human DNA. However, scientists are still debating the role of DNA with one group believing that up to 98 percent of it is only a relic of individual and collective genetic histories of a person.

However, the release 10 years later of the findings of project ENCODE - prepared by 442 researchers - which is an encyclopaedia of DNA elements, came up with the theory that up to 80 percent of DNA was not “junk” at all. According to New York Post’s Science reporter John Parrington, ENCODE appears to shed new light on links between the genome and common ailments such as cardiovascular diseases, diabetes, auto-immune conditions and mental disorders.

But critics of ENCODE say the researchers confused gene activity with functionality, said Parrington.

The warning by Annas and Elias not to rely too much on DNA is timely for two reasons. One is the relatively affordable cost of DNA test, down to $99 from $1 million in 2007. Another is the highly publicised surgeries of actress Angelina Jolie who had her breasts and ovaries removed after DNA tests showed she is at risk of cancer.

The two cites the case of Robert Green, a geneticist at Harvard Medical School, who was discovered through a DNA test to have a rare mutation that causes Treacher Collins syndrome. It is a condition that could result in disfigurement because of atypical facial bone development. But Green’s face was not disfigured, prompting the authors to emphasise, “Genes are not destiny.”

Jolie’s double mastectomy, though, was an exception because of her family history, three of whom died of BRCA 1-related cancers. Doctors believe she had done it just right, which was 10 years before 49, when Jolie’s mother was first diagnosed. Jolie was 39 when she had the double mastectomy.

Her case, nevertheless, terrified doctors who fear many women would follow Jolie’s example like one woman who went through the same procedure after discovery of a mutation of unknown significance which turned out later to be “unrelated to an increase in the occurrence of breast cancer.”

“Genomic Messages” was published by Harper Collins and went on sale on June 23. It costs $26.99. The book received critical praise from medical experts such as Dr Jerome Kassiser, medical editor-in-chief emeritus of The New England Journal of Medicine who wrote that the public’s health, privacy and peace of mind could be placed in peril if they don’t heed the book’s compelling content and insightful advice.

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