American history as seen through a genomic lens

Americans’ curiosity about their genetic heritage has helped reveal wider patterns of genetic mixing among distinct ethnic groups in North America, demonstrating how genetics can contribute to a better understanding of ancient and even relatively recent historic events. Scientists at Harvard Medical School and the consumer genetic testing company 23andMe (Mountain View, California) parsed the genetic data of 23andMe customers and combined that information with responses to survey questions about ethnicity and racial identity to create maps of the genetic landscape of the United States. Based on anonymized data from more than 160,000 consenting customers, the study traces the lingering genetic stamp of events such as the forced movements of Native Americans, Spanish colonization, and the aftermath of the slave trade. The data, published in the 8 January 2015 issue of the American Journal of Human Genetics, buttresses our understanding of these historic events and identifies newly revealed patterns such as the tendency of individuals with even small amounts of African-American ancestry to self-identify as African-American. Individuals who self-identified as of European ancestry had little evidence of interracial mixing that could be traced to Africa. Conversely, nearly all people who self-identified as African-American had some European genetic heritage, reflecting in part the shameful legacy of slavery. While the study is inherently biased by the self-selected nature of the participants, the sample does reflect census figures and provides a first look at the genomic legacy within us all. —Karyn Hede, News Editor

Computers reveal gene-splicing defects contributing to cancers, autism

Training a computer to recognize genetic variants that affect RNA splicing has yielded a bonanza of new potential contributors to diseases such as cancer and autism. A team of scientists, led by Brendan Frey of the University of Toronto, Ontario, Canada, reported “widespread patterns of mutation-driven aberrant splicing” in the 9 January 2015 issue of Science. Comparing whole-genome sequence data from people with and without autism, their machine-learning method not only identified variants already linked to autism but also flagged new variants that likely contribute to splicing defects. They reported that many of the variants were found in noncoding introns and therefore would not have been identified by exome analysis. Using the same method to probe genomic differences in colorectal cancer and spinal muscular atrophy, the study revealed new information about variants that cause gene-splicing defects and thus likely contribute to disease. Based on these findings, the authors predict that incorporating regulatory models into genomic studies will be necessary and fruitful for more accurately predicting which genetic alterations contribute to disease. This systematic exploration of noncoding DNA using unbiased computational techniques demonstrates a first step toward harnessing artificial intelligence to do just that. —Karyn Hede, News Editor

Genetics in Medicine Mission Statement

Genetics in Medicine is a monthly journal committed to the timely publication of:

  • Original reports which enhance the knowledge and practice of medical genetics

  • Strategies and innovative approaches to the education of medical providers at all levels in the realm of genetics

As the official journal of the American College of Medical Genetics and Genomics (ACMG), the journal will:

  • Provide a forum for discussion, debate and innovation concerning the changing and expanding role of medical genetics within the broader context of medicine

  • Fulfill our responsibility to the College membership through the publication of guidelines, policy statements and other information that enhances the practice and understanding of medical genetics

Finally, as genetics becomes increasingly important in the wider medical arena, we will be an accessible and authoritative resource for the dissemination of medical genetic knowledge to providers outside of the genetics community through appropriate reviews, discussions, recommendations and guidelines.