
By Carol Guzman
Advancements and discoveries in
genetic research and technologies intentioned to help all humans only benefit
few. Since the completion of the Human Genome Project in 2003, researchers have
sequenced the genomes of various populations all over the world (see: 1,000 Genomes
Project). Yet little population-specific research has been conducted
to advance the knowledge of disease and personalized medicine in minority
groups.
Genome-wide associate studies
(GWAS) allow scientists to study and identify genetic markers that
are involved in human disease. GWAS compare one group of healthy individuals against
a group of individuals affected by a specific disease. In these studies,
scientists look at several small gene changes called single nucleotide
polymorphisms (SNPs) in both sample populations. GWAS has been used to study
genetic factors that contribute to many common, complex conditions such as
diabetes, heart disease, and drug metabolism. The small genetic differences found in the
affected group versus the unaffected group help scientists identify genetic
variants that may be associated with an individual’s risk of developing a
specific disease. After GWAS are used to pinpoint genetic markers associated
with diseases, scientists can use this information to guide drug development that
treats the root cause of the disease rather than only treating the diseases’
symptoms.
According to a study conducted by
Nature, of 2,511 GWAS involving 35
million participants, 81% of participants were of European descent. Of the 19%
of non-European ancestry samples, African and Latin American ancestry, Hispanic
people and native or indigenous people represented less than 4% of the participants
the GWAS studies. Therefore, researchers are developing drugs and other
targeted therapies based on disease-associated genetic markers that are typically
found in only European populations. Failure to include minority populations
results in undiscovered genetic variants associated to diseases. These
exclusions make it impossible to make drugs that could treat the root causes of
minority genetic variants.
However, finding genetic markers
associated for a disease is not as easy as diversifying the population of those
participating in the study. The small genetic differences that would be
identified could also be natural genetic variation related to differences in
race or ethnicity, as opposed to variants associated with a disease. Therefore,
we must have global genomic studies to ensure that personalized medicine
benefits all human populations. The National Institutes of Health is making a
historic effort to gather data from more than one million people in the United
States. Their All of Us Research Program will enable researchers to conduct genetic
studies on various minority populations in the United States. Still, similar
initiatives have yet to be seen on a global scale.
Genetic diversity also plays an
important role in better understanding genes that are known to causes certain
diseases, such as genes related to hereditary cancer risk. The Jewish population
has an increased risk of having a gene mutation that leads to higher breast
cancer risk. Knowledge of specific Jewish genetic variants has helped
widespread hereditary cancer screening efforts within the Jewish community.
African women are also more likely to develop breast cancer compared to the
general population. However,
it was only this year that University of Chicago conducted the first study focused
on understanding genetic variants for breast cancer in African populations.
Among African women, breast cancer is diagnosed at later stages, is more
frequently a triple-negative disease, and is far more frequently fatal compared
to women of other of other ethnicities.
While in some ways the Jewish
population remains at the forefront of genetic screening we too suffer from the
marginalization instituted from lack of diversity in genetic research.
A clear example is the W1282X
nonsense mutation of cystic fibrosis, a variant of CF that is highly prevalent among
Ashkenazi Jews. This CF genetic variant affects 5-10% of CF cases worldwide. Researchers
have created drugs that help 90-95% of CF patients with the most common CF mutations,
but none have been made to help those suffering from CF by way of this
particular nonsense mutation.
Modern day Jews come from various
ethnic Jewish origins resulting in several Jews having different genetic
variants of various diseases. By integrating minority populations in genetic
studies to improve screening and genetic medicine, the scientific community benefits
Jews and the world.