From the Guidelines
Genetic risk factors for type 2 diabetes vary significantly among different racial and ethnic groups, with African populations commonly showing risk variants in TCF7L2 and KCNJ11 genes, though with different specific mutations than other groups. The distribution of genes for type 2 diabetes among racial groups is a complex issue, with various studies highlighting the differences in genetic risk factors across different populations. According to a study published in Diabetologia in 2022 1, genome-wide association studies (GWAS) have identified over 400 risk loci for type 2 diabetes, but most of these studies have been conducted in European populations. However, recent studies have focused on African populations, including the Africa America Diabetes Mellitus (AADM) study, the Durban Diabetes Study (DDS), and the Human Heredity and Health in Africa (H3Africa) Initiative.
Some key points to consider include:
- East Asians often carry variants in the KCNQ1 gene that increase diabetes risk
- South Asians frequently have variants in TCF7L2 and PPARG genes that affect insulin secretion and sensitivity
- African populations commonly show risk variants in TCF7L2 and KCNJ11 genes, though with different specific mutations than other groups
- Hispanic/Latino populations often carry risk variants in SLC16A11 and HNFA1 genes that are relatively uncommon in non-Hispanic whites
- European populations typically show risk variants in TCF7L2, KCNJ11, and PPARG genes
These genetic differences help explain why diabetes prevalence and presentation vary across ethnic groups, with some groups developing diabetes at lower BMI levels or showing greater insulin resistance. For example, a study published in Diabetologia in 2022 1 found that the pathophysiology of type 2 diabetes in Black Africans is different from that in their European counterparts, with hyperinsulinaemia due to a combination of increased insulin secretion and reduced hepatic insulin clearance being the primary defect. Understanding these differences is crucial for developing personalized prevention strategies and treatment approaches that account for a patient's genetic background, potentially improving diabetes management outcomes across diverse populations 1.
From the Research
Distribution of Genes for Type 2 Diabetes Among Racial Groups
- The distribution of genes for type 2 diabetes varies among different racial and ethnic groups, with some populations having a higher risk of developing the disease 2, 3.
- Studies have shown that the frequencies of type 2 diabetes susceptibility genetic alleles differ among racial and ethnic groups, but the relative contributions of genetic and environmental factors to these differences are not well understood 4.
- Research has identified certain genetic variants that are commonly associated with type 2 diabetes and its complications, but the frequencies of these variants vary among different populations 3.
- For example, a study found that the variant alleles of certain single nucleotide polymorphisms are highly prevalent in European and admixed American populations, but less common in African and Asian populations 3.
Genetic and Environmental Factors
- Both genetic and environmental factors play important roles in the pathogenesis of type 2 diabetes, and understanding the interplay between these factors is crucial for developing effective prevention and treatment strategies 5, 6.
- Environmental factors such as diet, socioeconomic status, and access to healthcare can contribute to the development of type 2 diabetes, and these factors can vary among different racial and ethnic groups 4, 5.
- Genetic factors, such as the calpain-10 gene, have been implicated in the development of type 2 diabetes, but identifying the specific genetic variants that affect risk is a challenging task 6.
Importance of Diversity in Genetic Studies
- Increasing population diversity in genetic studies of type 2 diabetes is essential for understanding the genetic basis of the disease and developing effective prevention and treatment strategies for all populations 2.
- Most genetic studies of type 2 diabetes have been performed in individuals of European ancestry, but expanding these studies to include diverse populations can provide valuable insights into the genetic and environmental factors that contribute to the disease 2.