Osteoporosis and Genetics

Osteoporosis is a common multifactorial disease of reduced bone mass that often leads to fracture. It affects people of both sexes, all racial groups, and people of all ages, though it is most common in the elderly.

Multiple environmental factors are involved in the production and development of disease. Some people have a strong genetic tendency to get osteoporosis.

From family histories, twin studies, and molecular genetics, it is quite evident now that some of the predisposition for osteoporosis can be inherited. Genetic control of osteoporosis is polygenic, meaning that several genes control it at once. The specific genes involved are beginning to be enumerated and identified by research.

Gene Variance

Researchers have discovered that both structural and regulatory genes are implicated in the tendency toward osteoporosis. Variance, or mutation in genes that control bone mass and bone turnover, or remodeling appear to be obvious but as everyone knows, genetics is a complex and often controversial science.

Identification of susceptibility genes for osteoporosis is one of several important approaches toward the long-term goal of understanding the molecular biology of the normal variation in bone strength and how it may be modified to prevent osteoporosis.

As with all genetic studies in humans, these advances in science need to be made in an environment of ethical safeguards that are acceptable to the general public. Finding the susceptibility genes underlying osteoporosis requires identifying specific alleles that are coinheritors with key heritable phenotypes in bone strength.

Because of the close correspondence among mammalian genomes, identification of the genes underlying bone strength in mammals such as the mouse is likely to be of major assistance in human studies.

New Field

While many of the non-genetic factors contributing to the risk for the disorder have been widely investigated in recent decades, the search for genetic determinants is relatively new, although very intense.

Researchers have as of yet been unable to identify one single cause. As with many medical conditions, genetic and non-genetic factors interact with each other to intensify or alleviate the problem. However, more and more molecular information concerning the genetic aspects of osteoporosis are becoming available almost on a daily basis.

With this information there is an ever-increasing likelihood for the design of new drugs to treat, reverse, or prevent the devastating effects of osteoporosis and hope for new tests that will identify those at risk for the disorder. So far researchers have identified a link between the Vitamin D receptor gene, Estrogen receptor genes and the genes that encode collagen, an important bone protein.

What is known is that your genes affect the peak bone mass that can be reached, usually around age 25. If there is a strong genetic tendency to get osteoporosis, the peak bone mass that is reached at skeletal maturity may be lower than average, indicating an increased risk for osteoporosis. If osteoporosis runs in your family, it may not be possible for you to prevent it. Extra precaution should be taken not to compound the risk with other known environmental factors.