Week 4 Post 1-Genetic Testing Inequalities

  Basic Information about Genetic Testing

-99.9% of humans share the same DNA, but in the .1% that is different there can be a lot of variety, as it accounts for the differences between all humans 

-Recently sequencing genomes has been used in much genetic research because it allows scientists to target specific mutations, either SNPs (Single Nucleotide Polymorphisms) or multiple mutations, and figure out if a particular difference in a gene causes a disease 

-These studies could be very useful in the future as CRSPR technology may make it easier to edit and fix those mutations 

-The human genome project was established in 2001 with the task of sequencing the human genome, which was a success, so the project expanded to sequencing a small population of volunteers, most of which were white

    -Most genome wide association studies (GWAS) still base their research off of this very limited data base

    -Since then the general genetic database has expanded greatly in number of people involved, but almost 90% of data comes solely from people of European descent 

-Often tiny changes in hundreds or even thousands of genes can add up to a risk for, or a protection from, a particular disease, And GWAS are the foundation for drug development and clinic guidelines

The Consequences of  Lack of Genetic Diversity

-Only including mostly European genetics is harmful to scientific research because it may overlook certain genetic sequences that are significant to research, but that are only present in populations that evolved in a specific environment

    -Due to migration and the environmental factors in an area, people who lived in certain regions evolved to their environment, which means their genetics changed, and are slightly different than people who were surrounded by different environmental factors 

    -People from different regions in the past, only reproduced with people from their region, and so if a mutation occurred it was highly likely that it stayed in the population in which it arose, meaning that if there is only data from one region, mutations that occurred in other reasons may be unknown 

        -Different locations of mutations can still cause the same effects, so people who have the same disease might have slightly different mutations

-A study by the Population Architecture using Genomics and Epidemiology (PAGE) found that conclusions based on the current genetic database could not be applied to the world population, because there is a bias towards genetic risk variants in Europeans 

     -They determined current risk scores, that are based on European genetics, could not be arcuately translate to Non-European populations

-There are many examples of genes found to be more likely in be variant in certain minority populations, that can cause or increase a person's risk for a disease, that if unknown would make treatment less effective or not possible

     -For example there is a gene variant, that is way more likely in people with African ancestry, that lowers the level of C-reactive protein, which is a biomarker in the blood that is used to detect inflammation related disease

         -Patients may be struggling with these diseases, like rheumatoid arthritis and lupus, but may not get the correct treatment, because the biomarker shows that there is nothing wrong in that region

-Another reason that the lack of regional diversity is harmful is because there are certain genes that if they have a variant will cause a disease regardless of the population or environment, but there are also some genes called different causative variants, that will only have effects on a person if they are from a certain population or face certain environmental factors, such as diet or activities 

    -This is harmful because again, treatments that are based on a gene could exclude or be less effective because of this overlook in populational differences. There also would be a lack of treatment for these variants from other populations because the cause of them would be unknown if just one population was studied

-Red blood cells are an incredibly important trait to many clinical studies, and there were around 500 known locations of the genome, found by GWAS, but a new study, which focused on comparing African American and Hispanic populations to European ones, in regards to red blood cells and found 11 new conditionally independent association signals, which are specific to people with African American and Hispanic ancestry

-By leaving out certain genetic populations in studies that are the basis for treatments, those treatments are then less effective or ineffective for certain populations, creating an inequity in healthcare based on region of origin 

The Legacy of Unequal Healthcare

-In the United States currently white people receive high quality healthcare than POC, and the morality rate is going down at unequal rates between white people and non-white people

-Only 4% of doctors are black in the US, compared to 13% of the  general population they make up 

    -Doctors can often have implicit racial biases against people of color, meaning they get access to worse healthcare

-Medical racism has often been based on the myth that black people have inferior bodies, which has led to many unethical and awful experiments, that treated black people as sub human

-In 2019 a healthcare algorithm, which was used by millions of doctors to allocate health care to patients was found to have a racial bias against black people, being less likely to refer them than equally sick white people

-People of color's pain is often perceived as less than it actually is by medical professionals, and they get systemically worse quality healthcare

Sources:

-Hodonsky CJ, Baldassari AR, Bien SA, Raffield LM, Highland HM, Sitlani CM, Wojcik GL, Tao R, Graff M, Tang W, Thyagarajan B, Buyske S, Fornage M, Hindorff LA, Li Y, Lin D, Reiner AP, North KE, Loos RJF, Kooperberg C, Avery CL. “Ancestry-specific associations identified in genome-wide combined-phenotype study of red blood cell traits emphasize benefits of diversity in genomics”. BMC Genomics. 2020 Mar 14. https://pubmed.ncbi.nlm.nih.gov/32171239/  

-Sirugo Giorgio, Williams M Scott, Tishkoff Sarah, “The Missing Diversity in Human Genetic Studies”. Cell, Volume 177, Issue 1, P26-31, March 21, 2019. https://www.cell.com/cell/fulltext/S0092-8674(19)30231-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867419302314%3Fshowall%3Dtrue  

-Williams David, Rucker Toni, “Understanding and Addressing Racial Disparities in Health Care”, Health Care Financ Rev, ncbi, Volume 21, Issue 4, P75–90, Summer 2000. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4194634/  

-Mapes Diane, “Lack of Diversity in Genetic Research is a Problem”, Fred Hutch Cancer Research Center, June, 19, 2019. https://www.fredhutch.org/en/news/center-news/2019/06/lack-diversity-genetic-research-problem.html  

-"A Brief History of Racism in Healthcare" A brief history of racism in healthcare | World Economic Forum (weforum.org)

-