''We now recognise some nouns, verbs and objects, but there is an awesome amount we don't yet understand,'' Suthers says.
While geneticists discover new gene mutations daily, it can take years to determine whether they cause disease, contribute to disease-risk or are harmless variations, Martin Delatycki says.
''I spend a lot of my time talking to patients about uncertainty,'' he says.
For these reasons, many researchers, including Suthers and Delatycki, are concerned by the rapid and unregulated rise of direct-to-consumer genetic tests.
The complex relationship between genes and disease can bewilder unqualified people who can easily misinterpret their test results, Delatycki says.
Genetic testing has consequences for life insurance, as people must declare if they are at risk of certain diseases.
Ethicist Jacqueline Savard says a lot of genetic information is meaningless to people's everyday lives, and society risks creating a population of ''worried well''.
''Sometimes you can know too much,'' says Savard, who is completing a PhD at the University of Sydney on people's perceptions and expectations of genetic testing.
Some people will place too much emphasis on the idea they might get a disease rather than living their life, she says.
But as the US geneticist Francis Collins said in 2010 on the 10th anniversary of the human genome project he helped to lead: ''We invariably overestimate the short-term impacts of new technologies and underestimate their longer-term effects.''
For people such as Chontell Johnson, these longer-term possibilities are the difference between life and death.
''I'm not living in the hope something will happen, but I am hopeful every minute of my life,'' she says.
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