Unveiling the Subtleties of Genetics: Exploring Regional Genomic Mapping Approaches
In the quest to unravel the genetic basis of complex traits, researchers have developed advanced methods like Regional Genomic Relationship Mapping (RGM) and Regional Heritability Mapping (RHM). These approaches go beyond traditional Genome-Wide Association Studies (GWAS) by considering the effects of multiple alleles within a genomic region that might be too subtle to detect when analyzing single nucleotide polymorphisms (SNPs) individually.
Understanding Regional Association
Regional Genomic Relationship Mapping (RGM) offers a way to integrate variance contributed by gametes in a population, which can help in estimating the heritability attributable to a small genomic region. This is particularly useful for detecting multiple alleles in a region that each contribute minimally to variance on their own (Nagamine et al., 2012).
Regional Heritability Mapping (RHM) enhances the ability to capture genetic variance that GWAS might miss, particularly useful in both related and unrelated populations. It has shown greater power in detecting rare variants and those with multiple independent effects within a region (Uemoto et al., 2013).
Advantages Over Traditional GWAS
Detection of rare variants: RHM can detect rare genetic variants that traditional GWAS often overlook, which can be essential for understanding the genetic architecture of complex traits like disease susceptibility or physical attributes (Wu et al., 2011).
Capturing more genetic variance: Both RGM and RHM can capture a larger proportion of genetic variance than GWAS, identifying additional trait loci and providing a more comprehensive understanding of trait heritability (Resende et al., 2017).
Reference:
Resende, R., Resende, M., Silva, F., Azevedo, C., Takahashi, E., Silva-Junior, O., & Grattapaglia, D. (2017). Regional heritability mapping and genome-wide association identify loci for complex growth, wood and disease resistance traits in Eucalyptus.. The New phytologist, 213 3, 1287-1300 .
Uemoto, Y., Pong-Wong, R., Navarro, P., Vitart, V., Hayward, C., Wilson, J., Rudan, I., Campbell, H., Hastie, N., Wright, A., & Haley, C. (2013). The power of regional heritability analysis for rare and common variant detection: simulations and application to eye biometrical traits. Frontiers in Genetics, 4.
Wu, M., Lee, S., Cai, T., Li, Y., Boehnke, M., & Lin, X. (2011). Rare-variant association testing for sequencing data with the sequence kernel association test.. American journal of human genetics, 89 1, 82-93 .
Resende, R., Resende, M., Silva, F., Azevedo, C., Takahashi, E., Silva-Junior, O., & Grattapaglia, D. (2017). Regional heritability mapping and genome-wide association identify loci for complex growth, wood and disease resistance traits in Eucalyptus.. The New phytologist, 213 3, 1287-1300 .