Diseases affect racial groups differently, especially when they are co-related with class disparities. For instance, a study conducted by the
National Health Service checks program in the United Kingdom, which aims to increase diagnosis across demographics, noted that "the reported lower screening in specific black and minority ethnic communities... may increase inequalities in health." In this specific case, the lack of attention to certain demographics can be seen as a cause of increased instances of disease from this lack of proper, equal preventive care. One must consider these external factors when evaluating statistics on the prevalence of disease in populations, even though genetic components can play a role in predispositions to contracting some illnesses. Individuals who share a similar genetic makeup can also share certain propensity or resistance to specific diseases. However, there are confronted positions in relation to the utility of using 'races' to talk about populations sharing a similar genetic makeup. Some geneticists argued that human variation is geographically structured and that genetic differences correlate with general conceptualizations of racial groups. Others claimed that this correlation is too unstable and that the genetic differences are minimal and they are "distributed over the world in a discordant manner". Therefore, race is regarded by some as a useful tool for the assessment of genetic epidemiological risk, while others consider it can lead to an increased underdiagnosis in 'low risk' populations.
Single-gene disorders There are many
autosomal recessive single gene
genetic disorders that differ in frequency between different populations due to the region and ancestry as well as the
founder effect. Some examples of these disorders include: •
Cystic fibrosis, the most common life-limiting
autosomal recessive disease among people of Northern European heritage •
Sickle-cell anemia, most prevalent in populations with sub-Saharan African ancestry but also common among Latin-American, Middle Eastern populations, as well as those people of South European regions such as Turkey, Greece, and Italy •
Thalassemia, most prevalent in populations having Mediterranean ancestry, to the point that the disease's name is derived from Greek
thalassa, "sea" •
Tay–Sachs disease, an autosomal recessive disorder most common among
Ashkenazi Jews,
French Canadians of
Saguenay–Lac-Saint-Jean,
Cajuns of
Louisiana and
Old Order Amish of
Pennsylvania •
Hereditary hemochromatosis, most common among persons having Northern European ancestry, in particular those people of
Celtic descent •
Hermansky–Pudlak syndrome, most common among
Puerto Ricans •
Finnish heritage diseases, autosomal recessive diseases that are far more common among
Finns Multifactorial polygenic diseases Many diseases differ in frequency between different populations. However, complex diseases are affected by multiple factors, including genetic and environmental. There is controversy over the extent to which some of these conditions are influenced by genes, and ongoing research aims to identify which genetic loci, if any, are linked to these diseases. "Risk is the probability that an event will occur. In epidemiology, it is most often used to express the probability that a particular outcome will occur following a particular exposure." Different populations are considered "high-risk" or "low-risk" groups for various diseases due to the probability of that particular population being more exposed to certain risk factors. Beyond genetic factors, history and culture, as well as current environmental and social conditions, influence a certain population's risk for specific diseases.
Disease progression Racial groups may differ in how a disease progresses. Different access to healthcare services, different living and working conditions influence how a disease progresses within racial groups. However, the reasons for these differences are multiple, and should not be understood a consequence of genetic differences between races, but rather as effects of social and environmental factors affecting. Some geneticists have determined that "
human genetic variation is geographically structured" and that different geographic regions correlate with different races. Meanwhile, others have claimed that the human genome is characterized by clinal changes across the globe, in relation with the
"Out of Africa" theory and how migration to new environments cause changes in populations' genetics over time. Some diseases are more prevalent in some populations identified as races due to their common ancestry. Thus, people of African and Mediterranean descent are found to be more susceptible to
sickle-cell disease while
cystic fibrosis and
hemochromatosis are more common among European populations.
Race-based treatment Racial groups, especially when defined as minorities or ethnic groups, often face structural and cultural barriers to access healthcare services. The development of culturally and structurally competent services and research that meet the specific health care needs of racial groups is still in its infancy. Scientific studies have shown the lack of efficacy of adapting pharmaceutical treatment to racial categories. "Race-based medicine" is the term for medicines that are targeted at specific racial clusters which are shown to have a propensity for a certain disorder. The first example of this in the U.S. was when
BiDil, a medication for congestive heart failure, was licensed specifically for use in American patients that self-identify as black. Previous studies had shown that African American patients with congestive heart failure generally respond less effectively to traditional treatments than white patients with similar conditions. After two trials, BiDil was licensed exclusively for use in African American patients. Critics have argued that this particular licensing was unwarranted, since the trials did not in fact show that the drug was more effective in African Americans than in other groups, but merely that it was more effective in African Americans than other similar drugs. It was also only tested in African American males, but not in any other racial groups or among women. This peculiar trial and licensing procedure has prompted suggestions that the licensing was in fact used as a race-based advertising scheme. Critics are concerned that the trend of research on race-specific pharmaceutical treatments will result in inequitable access to pharmaceutical innovation and smaller minority groups may be ignored. This has led to a call for regulatory approaches to be put in place to ensure scientific validity of racial disparity in pharmacological treatment. An alternative to "race-based medicine" is personalized or precision medicine. Precision medicine is a
medical model that proposes the customization of
healthcare, with medical decisions, treatments, practices, or products being tailored to the individual patient. It involves identifying genetic, genomic (e.g.
whole genome sequencing), and clinical information—as opposed to using race as a proxy for these data—to better predict a patient's predisposition to certain diseases. ==Environmental factors==