Emory University scientists have identified and created a map of more than 400,000 insertions and deletions (INDELs) in the human genome that signal a little-explored type of genetic difference among individuals. INDELS are an alternative form of natural genetic variation that differs from the much-studied single nucleotide polymorphisms (SNPs). Both types of variation are likely to have a major impact on humans, including their health and susceptibility to disease.
The INDEL research, led by Scott Devine, PhD, assistant professor of biochemistry at Emory University School of Medicine, has been posted online and will be published in the September issue of the journal Genome Research.
The human genome sequence in our DNA contains three billion base pairs of four chemical building blocks Ð adenine, thymine, cytosine, and guanine (A, T, C, G), strung together in different combinations in long chains within 23 pairs of chromosomes. When the first human genome was being sequenced, it became apparent that additional human genomes would have to be sequenced to identify the places in the genetic code that account for human variation. Scientists now know that humans share about 97-99 percent of the genetic code, and the remaining 1-3 percent dictates individual differences. These naturally occurring differences, called polymorphisms, help explain differences in appearance, susceptibility to diseases, and responses to the environment.
SNPs are differences in single chemical bases in the genome sequence, and INDELs result from the insertion and deletion of small pieces of DNA of varying sizes and types. If the human genome is viewed as a genetic instruction book, then SNPs are analogous to single letter changes in the book, whereas INDELs are equivalent to inserting and deleting words or paragraphs.
Most polymorphism discovery projects have focused on SNPs, resulting in the International HapMap Project Ð a catalog and map of more than 10 million SNPs derived from diverse individuals throughout the globe. Dr. Devine and postdoctoral researcher Ryan Mills, PhD, focused instead on INDELs, using a computational approach to examine DNA re-sequences that originally were generated for SNP discovery projects. Thus far they have identified and mapped 415,436 unique INDELs, but they expect to expand the map to between 1 and 2 million by continuing their efforts with additional human sequences.
Dr. Devine says INDELs can be grouped into five major categories, depending on their effect on the genome: (1) insertions or deletions of single base pairs; (2) expansions by only one base pair (monomeric base pair expansions); (3) multi-base pair expansions of 2 to 15 repeats; (4) transposon insertions (insertions of mobile elements); (5) and random DNA sequence insertions or deletions. INDELs already are known to cause human diseases. For example, cystic fibrosis is frequently caused by a three-base-pair deletion in the CFTR gene, and DNA insertions called triplet repeat expansions are implicated in fragile X syndrome and Huntington's disease. Transposon insertions have been identified in hemophilia, muscular dystrophy and cancer.
"Were entering an exciting new era of predictive health where an individuals personal genetic code will provide guidance on healthcare decisions says Dr. Devine. "Our maps of insertions and deletions will be used together with SNP maps to create one big unified map of variation that can identify specific patterns of genetic variation to help us predict the future health of an individual. The next phase of this work is to figure out which changes correspond to changes in human health and develop personalized health treatments. This could include specific drugs tailored to each individual, given their specific genetic code.
Ultimately, each person's genome could be re-sequenced in a doctor's office and his or her genetic code analyzed to make predictions about their future health. Dr. Devine believes the technology holds the promise of predicting whether a person will develop diabetes, mental disorders, cancer, heart disease and a range of other conditions.
Holly Korschun | EurekAlert!
Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex
New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Materials Sciences
22.06.2018 | Earth Sciences
22.06.2018 | Life Sciences