Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Studies on human genome variation provide insight into disease


The International HapMap Project was initiated with the primary goal of facilitating medical studies and understanding the genomic basis for human diseases. To coordinate with the journal Nature’s publication describing the HapMap, the journal Genome Research is announcing a special issue entitled "Human Genome Variation," which is entirely devoted to studies using these data to provide insight into human biology and disease.

Predicting pregnancy success

Successful human reproduction and the maintenance of early pregnancy are dependent on a cluster of genes on chromosome 19 called the Luteinizing Hormone/Chorionic Gonadotropin Beta (LHB/CGB). During primate evolution, this cluster actively underwent numerous gene duplications and structural rearrangements, allowing the associated genes to acquire new biological functions.

In this month’s issue of Genome Research, Dr. Maris Laan and her colleagues report their analysis of the LHB/CGB cluster in three human populations: European Estonians, African Mandenka, and Chinese Han. They demonstrate how gene conversion was critical for shaping the genetic diversity of this region in humans.

"This study paves the way for examining an individual’s potential reproductive success based on sequence variants of the LHB/CGB genes," explains Laan. "We may be able to determine whether an individual is particularly susceptible to spontaneous abortions or reduced gonadal function, for example."

Maris Laan, Ph.D.
Research Professor, University of Tartu, Estonia
Phone: +372-53495258

X-ing out hereditary prostate cancer

According to the Prostate Cancer Foundation, one of every six American men develops prostate cancer, making it the most common form of non-skin cancer. Growing evidence suggests that there is a significant hereditary component to the disease, and one of the most strongly associated genomic regions lies on the X chromosome.

This X chromosomal region spans a cluster of five SPANX genes that are predominantly expressed in the testis and in certain tumors. In this month’s issue of Genome Research, Dr. Vladimir Larionov and his colleagues examined the genetic architecture of the SPANX cluster and showed how the region exhibited dynamic deletions, duplications, and gene conversion events, some of which may have resulted in the development of mutations involved in prostate cancer susceptibility.

"Because of the strong similarity among genes in this region, we had to develop a new technique for our mutational analysis, which we call TAR cloning," explains Larionov. "Using this method, we isolated the SPANX region from 200 individuals by recombination in yeast."

Based on their results, the authors speculate that predisposition to prostate cancer – at least in some individuals – is determined by the specific architecture of the SPANX gene cluster on the X chromosome. "We’re hoping to clarify which specific types of genomic rearrangements lead to prostate cancer susceptibility," says Larinov, "so that we can someday identify therapeutic targets for this disease."

Vladimir Larionov, Ph.D.
Head, Genome Structure and Function Section, National Cancer Institute
Phone: 301-496-7941

Genetic traffic in DiGeorge syndrome

One of the most common human genomic disorders, DiGeorge syndrome, occurs in one of every 2,000-4,000 live births and involves a deletion on chromosome 22. The deletion is mediated by rare repetitive sequences that flank genes crucial for proper development of the heart, face, and upper thorax.

Dr. Bernice Morrow and her colleagues describe in this month’s issue of Genome Research how they examined these flanking repetitive sequences for patterns of polymorphisms. "Our results show that there are intervals with more frequent traffic of genetic material – regions with higher rates of gene conversion or recombination – that are indicative of genomic instability," explains Morrow.

"With this knowledge in hand, we hope to screen our patients and identify the genomic mechanism underlying this important disease," says Morrow.

Bernice Morrow, Ph.D.
Professor, Albert Einstein College of Medicine
Phone: 718-430-4274

Looking for genes in all the right places

Geneticists rely on variation, or alterations in DNA sequence, for disease-association studies. Hereditary traits such as heart disease, arthritis, and Alzheimer’s can be assigned to specific genomic regions based on their association with DNA markers.

The success of disease-association studies is dependent upon several characteristics of the DNA markers, including allelic frequency and genomic coverage. In some cases, a particular variant at one locus is perfectly associated with a specific variant at another locus; in other words, the two markers are "genetically indistinguishable."

Dr. Lon Cardon and his colleagues describe in this month’s issue of Genome Research how these "genetically indistinguishable" polymorphisms can complicate the identification of disease-related genes. "Although they should pose few difficulties when they are located close together on the same chromosome, they often occur on different chromosomes, where it is quite another story," explains Cardon. When this is the case, true disease genes cannot be distinguished from their anonymous genetic ’twins.’

"Research in human genetic variation is rapidly moving towards realizing our aims of improving diagnosis of common diseases such as diabetes and heart disease," says Cardon, "but the genome is tricky; it won’t reveal its secrets easily. The real disease-causing culprits can have many silent partners. We need to know the relationships of all these partners to focus on real disease mutations and to minimize attention on the innocent gene variants that colour the humanity of life."

Lon R. Cardon, Ph.D.
Professor of Bioinformatics, University of Oxford
Phone: +44-01865-287591

Maria A. Smit | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>