An international team supported in part by NIH has found evidence that common genetic variants linked to osteoarthritis may also play a minor role in human height.

Height Insights

An international team supported in part by NHGRI, NIA, NIDDK and NHLBI has found evidence that common genetic variants linked to osteoarthritis may also play a minor role in human height. The findings, released online in Nature Genetics, came from studies involving more than 35,000 people and a survey across the entire human genome. The new variants account for just a small fraction of the genetic basis of height: genetic factors are thought to be responsible for at least 80 percent of the variation in height among people; the new variants—along with another recently identified height-associated genetic variant—account for less than 1 percent of human height variation. However, researchers said it’s still exciting to be able to achieve findings like these. Understanding the factors involved in human height could provide new insights into osteoarthritis and other musculoskeletal diseases. Osteoarthritis is by far the most common type of arthritis, affecting nearly 21 million Americans.

Genetic Associations with Coronary Artery Disease

In a study also published in Nature Genetics and supported by several institutes, an international group of scientists reported the discovery of more than 25 genetic variants in 18 genes connected to cholesterol and lipid levels. This is significant because while we know that both environmental and genetic factors influence a person’s lipid levels (blood fat)—which are important risk factors for coronary artery disease (CAD)—more has been understood about the environmental contribution than the genetic role. The recently discovered variants—found through studies of more than 20,000 individuals and spanning the entire genome—could potentially open the door to strategies for the treatment and prevention of CAD.

Inheriting Autism Risk

Another variation on a gene: scientists funded by NIMH have found a gene variant that may raise the risk of children developing autism, especially when the variant is inherited from mothers rather than fathers. Published online in the American Journal of Human Genetics, the study results focused on a gene, CNTNAP2, that makes a protein that enables brain cells to communicate with each other through chemical signals and appears to play a role in brain cell development. Previous studies had implicated the gene in autism, but in this study researchers were able to link a specific variation in its structure to the disease. Inheriting the gene variant does not mean that a child will inevitably develop autism, just that the child may be more vulnerable to developing the disease than children without the variation. Autism is a highly heritable disease, so identifying genes involved with it is crucial to being able to map its pathology, researchers said. The disorder currently has no cure.

The Evolution and Resilience of MRSA

According to an NIAID-led study, community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are primarily caused by a single strain of an evolving bacterium that has spread throughout the U.S. during the last 5 years. The findings rule out the previously held possibility that multiple strains of USA300, the most troublesome type of CA-MRSA in the U.S., emerged randomly with similar characteristics. This study also offers a hypothesis for the origin of previous S. aureus outbreaks, such as those caused by penicillin-resistant strains in the 1950s and 1960s. A second study, also led by NIAID scientists, reveals new information about how MRSA bacteria in general elude the human immune system. Both studies, published in the Proceedings of the National Academy of Sciences and the Journal of Immunology, respectively, should add insight to the expanding knowledge base for MRSA, an emerging public health concern that typically causes readily treatable soft-tissue infections, but can also lead to life-threatening conditions that are difficult to treat.—compiled by Sarah Schmelling