Study Reveals Average Human Genome Contains 4.3-5.3 Million Variants
New research from the University of Exeter highlights the vast genetic diversity present in the average human genome, based on data from nearly 900,000 individuals.
The average human genome has between 4.3 to 5.3 million variants, with 1.5% classified as rare.
Individuals of African descent carry approximately one million more variants than other populations.
Each person is born with an estimated 61 new mutations, predominantly inherited from their fathers.
Researchers at the University of Exeter Medical School have unveiled a groundbreaking study detailing the genetic makeup of the average human genome. This research, which analyzed whole-genome sequences from nearly 900,000 adults sourced from the UK Biobank and the US-based All of Us program, reveals that the average genome contains between 4.3 and 5.3 million variants, with a small fraction, about 1.5%, being rare.
The study's lead author, Professor Caroline Wright, emphasized the significance of whole genome sequencing in diagnosing genetic disorders and its growing role in genetic screening for disease prediction. She noted that many individuals are unaware of the extensive genetic variation present in their genomes, stating, "Variation is the norm." This research provides essential insights for clinicians and patients, aiding in the understanding and interpretation of genomic data.
Among the findings, it was noted that most genetic differences are common within the population and occur outside of genes, suggesting they are unlikely to impact health significantly. However, the study identified that individuals of African ancestry possess about one million more variants on average compared to other demographic groups, a disparity attributed to the reference genome's composition, which primarily reflects European ancestry.
The research also highlighted that an average person carries around 229 variants that could potentially disrupt gene function, with only 72% of these being classified as high-confidence. Furthermore, individuals typically have one to three variants associated with inherited single-gene diseases, most of which are recessive, indicating that they are healthy carriers. The study also identified approximately 50 rare variants of uncertain significance, whose implications remain unclear.
Looking ahead, the researchers estimate that each person is born with about 61 new mutations, with a notable contribution from paternal age, where each additional year is linked to an increase in new mutations. The implications of these findings extend to genetic testing and screening programs, highlighting the importance of considering individual context, such as family history and environmental factors, when interpreting genetic data. The complete study is published in the journal Genome Medicine.
