Researchers from The University of Texas at Austin and New York Genome Center have achieved a significant breakthrough by harnessing the power of artificial intelligence to analyze vast medical imaging datasets, including X-ray images and genetic sequences. This pioneering study, featured as the cover article in the journal Science, not only sheds light on our evolutionary history but also opens doors to a future where physicians can more accurately assess a patient’s risk of developing conditions like back pain or arthritis later in life.
Led by Vagheesh Narasimhan, an assistant professor of integrative biology and statistics and data science, the multidisciplinary team utilized AI to create a genetic map of skeletal proportions. One fascinating discovery made during the research was the unique feature of humans having longer legs than arms, a crucial adaptation that enables bipedal locomotion. The scientists aimed to identify the genetic changes responsible for this distinct skeletal form seen in fossil records from early human ancestors like Australopithecus to Neanderthals. Additionally, they investigated how these skeletal proportions influence the risk of musculoskeletal diseases, such as knee and hip arthritis, which affect millions of people worldwide and are leading causes of adult disability in the United States.
To achieve their goals, the researchers employed deep learning models to automatically quantify measurements between various points in the body, such as shoulders, knees, and ankles, using 39,000 medical images. By correlating these measurements with individuals’ genetic sequences, they pinpointed 145 genetic locations that influence skeletal proportions. This novel genetic map offers developmental biologists a systematic approach to explore these genes’ roles further.
Furthermore, the team investigated the association between skeletal proportions and major musculoskeletal diseases, revealing intriguing connections. Individuals with a higher hip width-to-height ratio were more prone to developing osteoarthritis and hip pain. Similarly, people with higher ratios of femur length to height were more susceptible to knee arthritis, knee pain, and other knee-related issues. Additionally, those with a higher ratio of torso length to height were more likely to suffer from back pain.
The findings also have evolutionary implications, as some genetic segments that control skeletal proportions coincide more than expected with human accelerated regions. These regions are parts of the genome shared by great apes and other vertebrates but significantly differ in humans, providing genomic insights into the divergence of human skeletal anatomy.
This research evokes comparisons to Leonardo Da Vinci’s famous artwork “The Vitruvian Man,” which also explores the ratios and lengths of limbs in the human body. However, modern methods and genetic investigations now allow researchers to delve deeper into understanding the genetic determinants of basic human form and proportion, building on the legacy of the Renaissance master’s curiosity about human anatomy.
