One of the goals of genome sequencing is to identify genetic mutations associated with increased susceptibility to disease. Yet by and large these discoveries have been made in people of European or Asian ancestry, resulting in an incomplete picture of global genetic variation in disease vulnerability. In a new study published in the journal BMC Medical Genomics, researchers at the University of Pennsylvania (Penn) have addressed this omission. Their investigation identified more than 30 previously undescribed mutations in important regulatory molecules called microRNAs. Many of these mutations influence whether a person develops cancer or the severity of the disease. One variant has been associated with breast cancer mortality, and the team’s discovery could help explain why, once diagnosed with breast cancer, women with African ancestry are more likely to die from the disease than other women. Knowing about these differences could inform efforts to develop diagnostic tests or even treatments for diseases like cancer. Dr. Renata A. Rawlings-Goss, a postdoctoral fellow in the Department of Genetics in Penn’s Perelman School of Medicine, led the work, collaborating with the department’s Dr. Michael C. Campbell. Dr. Sarah Tishkoff, a Penn Integrates Knowledge professor with appointments in Penn Medicine’s Department of Genetics and the School of Arts & Sciences’ Department of Biology, was the study’s senior author. MicroRNAs, or miRNAs, are small molecules that are not translated into proteins, but rather, serve to regulate gene expression, usually by blocking protein production. A single miRNA can govern the expression of as many as 6,000 different genes, so a change in the way these molecules function can have significant biological effects.Login Or Register To Read Full Story