Nature versus nurture question addressed in landmark study

Genome sequencing has been used to determine how much genes influence human characteristics including height and weight, and susceptibility to diseases like Type 2 diabetes, in a study co-led by University of Queensland researchers and collaborators at genomic technology company Illumina, Inc.

This study is the largest of its kind and used the DNA sequences of 347,630 people of European descent from the UK Biobank to quantify how much trait differences between people can be explained by genetic factors, known as heritability.

Professor Loic Yengo from UQ’s Institute for Molecular Bioscience said whole genome sequencing allows the accurate measurement of most genetic variants, unlike traditional methods using data from relatives and twin studies.

“An outstanding question in human genetics has been how much twin-based estimates of heritability could be replicated using modern genomic technologies when applied to unrelated individuals,” Professor Yengo said.

“Our study answers this question and demonstrates for the first time that this approach works.”

Among the 34 characteristics and diseases the researchers studied were height, body mass index (BMI), cholesterol, hypertension, fertility, smoking initiation and heart disease.

“Across the traits studied, we’ve estimated genetic factors can explain on average 30 per cent of differences between people, ranging from 74 per cent for height and 12 per cent for fertility,” Professor Yengo said.

“One of the limitations of the traditional approach is that relatives and twins share not only genes but also environmental factors.

“For example, family-based estimates put genetic influence on a person’s BMI at 50 per cent, but the genomic sequencing determined the influence was 35 per cent.”

The next step is to map the genes or genetic variants between individuals to explain why some people develop disease and others don’t.

“That would allow at-risk individuals to be identified early, and preventative measures taken well in advance of the disease developing,” Professor Yengo said.

The research was funded by the Australian Research Council and the Snow Medical Research Foundation.

Co-author and Illumina Vice President of Artificial Intelligence Kyle Farh said population-level genomic datasets like UK Biobank give researchers access to a wealth of data”.

The research is published in Nature.