From
ethnic minorities
to the
elderly
, passing through
differences in income :
275 million hitherto unknown genetic variants
have emerged
from the
analysis of the DNA of often overlooked populations
.
It is one of the goals achieved thanks to 'All of Us', the international research program that aims to expand gene banks and whose results have been published in five articles in the journals Nature, Communications Biology and Nature Medicine.
"In recent years, a series of important technological improvements have made it possible to sequence the entire genome of an individual in a short time and at low costs, thus allowing the creation of large databases", Marco Pierotti of Cogentech, a benefit company, told ANSA. of the Institute of Molecular Oncology of the Airc - Ifom Foundation.
"But in these databases there are biases related to the population considered."
In fact, these are data relating almost exclusively to people from industrialized countries, especially Indo-Europeans, whites of middle or high social class, while there is little data relating to ethnic minorities.
A problem that can impact the effectiveness of new drugs, therapies or screening tools.
"These methods - added Pierotti - have made it possible, for example, to complete a vast study on the onset of ovarian and breast cancer by analyzing the entire DNA of 10,000 women who had developed it and to do the same on a similar group of almost 10,000 other women, similar in age, physical condition, ethnic group, who had not developed cancer".
By comparing the DNA of the two groups, it was thus possible to discover 313 markers, i.e. small DNA sequences that play a role in the development of that particular form of tumor.
"In this way it becomes possible, for example, to look for the presence of markers in a subject and understand the level of risk, therefore being able to be more precise when planning screenings", added the Italian researcher.
These are the so-called polygenic risks, i.e. the possibility of developing a disease due to the combined presence of a more or less large series of small genetic mutations.
But all this is only reliable if that type of patient is present in the initial database.
To try to eliminate this fundamental error, All of Us was born, the project that aims to update existing gene banks with the complete DNA of thousands of Americans from underrepresented categories, which include ethnic and racial groups (46%), people who live in poverty (26%) and elderly (28%).
A first tranche of 2,500 genomes has just been completed and 275 million new, hitherto little-known variants have immediately emerged, associated with risk factors for some diseases, from tumors to type 2 diabetes. It is
a result that promises to significantly improve the ability to predict possible high risks of developing a serious pathology even in subjects who until now were poorly represented in the databases.
However, the authors of the research underline, in order to reach an acceptable rate of completeness, it will be necessary to expand the range of genomes to at least 25 thousand complete DNAs.
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