Most People May Have High Genetic Risk for Three of 28 Common Diseases, Study Finds - Video

Almost everyone carries genetic variations linked to serious diseases, but having a higher genetic risk does not necessarily mean developing the condition. A new study suggests that the average person may fall into a high genetic risk category for nearly three common diseases, including diabetes, cardiovascular disease and schizophrenia.

Published in the journal Genome Medicine, the study led by researchers at the University of Exeter, UK, examined genetic variations across nearly one million individuals to better understand what constitutes an average human genome.

Researchers analysed whole-genome sequencing data from two large population databases, the UK Biobank and the US-based All of Us research programme.

The findings revealed that an average human genome contains approximately five million genetic variants, representing differences in DNA sequences between individuals.

Among these, around 10,000 variants alter gene sequences and may influence biological functions, including lactose tolerance and responses to medications. However, many genetic variations have little or no effect on health.

Importantly, researchers found that each individual carries approximately one to three rare genetic variants previously associated with serious inherited diseases, alongside around 50 rare variants whose clinical significance remains uncertain.

The team also examined polygenic risk scores, which estimate disease susceptibility by combining information from multiple genetic variants.

The analysis revealed that an average individual ranked among the top 10% of genetic risk for nearly three of the 28 common diseases assessed.

Additionally, approximately one in five individuals ranked within the highest 1% of genetic risk for at least one condition.

However, researchers emphasised that genetic susceptibility does not guarantee disease development. Family history, lifestyle, environmental exposures and existing health conditions also influence individual risk.

The findings underline the importance of interpreting genetic screening results within a broader clinical context rather than relying on genetic risk scores alone.

REFERENCE: Wright, H. I. W., et al. (2026). The average individual genome: a survey of nearly 1 million whole-genome sequences. Genome Medicine. DOI: 10.1186/s13073-026-01792-x.