More than 15 years after scientists first mapped the human genome, most diseases still cannot be predicted based on one's genes, leading researchers to explore epigenetic causes of disease. But the study of epigenetics cannot be approached the same way as genetics, so progress has been slow. Now, researchers at the USDA/ARS Children's Nutrition Research Center at Baylor College of Medicine and Texas Children's Hospital have determined a unique fraction of the genome that scientists should focus on. Their report, which provides a "treasure map" to accelerate research in epigenetics and human disease, was published in Genome Biology.

More than 15 years after scientists first mapped the human genome, most diseases still cannot be predicted based on one's genes, leading researchers to explore epigenetic causes of disease. But the study of epigenetics cannot be approached the same way as genetics, so progress has been slow. Now, researchers at the USDA/ARS Children's Nutrition Research Center at Baylor College of Medicine and Texas Children's Hospital have determined a unique fraction of the genome that scientists should focus on. Their report, which provides a "treasure map" to accelerate research in epigenetics and human disease, was published in Genome Biology.

Epigenetics is a system for molecular marking of DNA -- it tells the different cells in the body which genes to turn on or off in that cell type. But the cell-specific nature of epigenetics makes it challenging to study. Whereas a blood sample can be used to 'genotype' an individual, most epigenetic marks in blood DNA provide no clues about epigenetic dysregulation in other parts of the body, such as the brain or heart.

Dr. Robert A. Waterland, professor of pediatrics -- nutrition and of molecular and human genetics at Baylor, and his team identified special regions of the genome where a blood sample can be used to infer epigenetic regulation throughout the body, allowing scientists to test for epigenetic causes of disease.

To do this, they focused on the most stable form of epigenetic regulation -- DNA methylation. This addition of methyl groups to the DNA molecule occurs in the embryonic state and can impact health for your entire life.