Scientists have long expected to find genetic components of common traits and diseases in the human genome, but these components have been elusive. Studies suggest that traits like height are highly heritable, yet genome-wide association studies (GWAS) have only accounted for a small fraction of this heritability. Researchers have identified numerous genetic variants associated with height, but their individual effects are small, explaining only about 5% of the heritability. Similar issues exist for other traits and diseases, such as autism and schizophrenia, where heritability estimates are high but genetic explanations are lacking. The limitations of GWAS may explain the missing heritability. These studies focus on single nucleotide polymorphisms (SNPs), which may not capture the full genetic complexity. Other factors, such as copy-number variations (CNVs) and epistasis (gene interactions), may contribute to heritability but are difficult to detect. CNVs, which involve larger DNA segments, may explain some of the missing heritability, especially in complex diseases like schizophrenia and autism. Epistasis, where genes interact to influence traits, is another area that requires further investigation. Heritability estimates may also be flawed. They are based on comparing the heights of parents and children, but environmental factors can influence these estimates. Epigenetic changes, which affect gene expression without altering DNA sequence, may also play a role in heritability, though their mechanisms are not fully understood. Additionally, the complexity of genetic interactions and the influence of rare variants make it challenging to explain heritability fully. Despite these challenges, researchers remain optimistic that more of the missing heritability can be found. Advances in sequencing technology and the analysis of genetic networks may help uncover the genetic basis of common diseases. However, the field faces the challenge of translating genetic findings into clinical applications, as many genetic variants have only modest effects on traits and diseases. The search for missing heritability continues, highlighting the complexity of genetic and environmental interactions in human health.Scientists have long expected to find genetic components of common traits and diseases in the human genome, but these components have been elusive. Studies suggest that traits like height are highly heritable, yet genome-wide association studies (GWAS) have only accounted for a small fraction of this heritability. Researchers have identified numerous genetic variants associated with height, but their individual effects are small, explaining only about 5% of the heritability. Similar issues exist for other traits and diseases, such as autism and schizophrenia, where heritability estimates are high but genetic explanations are lacking. The limitations of GWAS may explain the missing heritability. These studies focus on single nucleotide polymorphisms (SNPs), which may not capture the full genetic complexity. Other factors, such as copy-number variations (CNVs) and epistasis (gene interactions), may contribute to heritability but are difficult to detect. CNVs, which involve larger DNA segments, may explain some of the missing heritability, especially in complex diseases like schizophrenia and autism. Epistasis, where genes interact to influence traits, is another area that requires further investigation. Heritability estimates may also be flawed. They are based on comparing the heights of parents and children, but environmental factors can influence these estimates. Epigenetic changes, which affect gene expression without altering DNA sequence, may also play a role in heritability, though their mechanisms are not fully understood. Additionally, the complexity of genetic interactions and the influence of rare variants make it challenging to explain heritability fully. Despite these challenges, researchers remain optimistic that more of the missing heritability can be found. Advances in sequencing technology and the analysis of genetic networks may help uncover the genetic basis of common diseases. However, the field faces the challenge of translating genetic findings into clinical applications, as many genetic variants have only modest effects on traits and diseases. The search for missing heritability continues, highlighting the complexity of genetic and environmental interactions in human health.