While it is known that there are several factors that play a role in the development of osteoporosis, the role of certain genes is an important consideration. Genes are the pieces of code that are contained within the chromosomes. These genes provide the blueprint for different parts of the human body, its structure, function and regulation – from the largest organ to the small molecule within a cell.

Defective genes cause abnormalities in the body, either in its structures or regulation of functions. There is no specific gene that has been isolated for osteoporosis. However, it appears that several genes may be partly responsible for the development of osteoporosis particularly in the presence of certain environmental and lifestyle factors.

Types of Osteoporosis Genes

There are several genes that appear to play a role in bone health without causing diseases of other organs. This is known as primary osteoporosis. It is also important to note that genetic diseases like cystic fibrosis can have a secondary effect on bone health hence the term secondary osteoporosis. However, osteoporosis genes specifically refers to genes that causes weak and brittle bones as is the case in osteoporosis.

Bone health is determined by several genes and it has now been discovered that as much as 56 regions in the human genome may be responsible for defects in bone structure. Some of these genes may also increase the risk of bone fracture. Not all of these genes are inherited – passed from parent to child. Sometimes these genetic defects arise due to certain factors in life. However, a strong family history is a major contributor to osteoporosis due to the passing down of genes.

Genes that are responsible for osteoporosis may have the following effects :

• Alter the response of the body to vitamin D which is an essential micronutrient in calcium metabolism – the mineral that makes strong bones. This is known as the VDR gene – vitamin D receptor gene.
• Affect the sensitivity to estrogen, a hormone that has a significant impact on bone tissue which itself has been shown to be sensitive to estrogen. Therefore the greater risk of osteoporosis in postmenopausal women – a phase in life marked by low estrogen levels. However, the role of the estrogen receptor gene is debated because not every women is affected to the same extent.
• Bone proteins that play a role in bone strength may be defective or deficient due to genetic factors. Here the genetic defects lead to abnormal bone proteins that do not allow for the same strength and structure as in healthy bone. Two such genes that have been identified are COLIA1 and COLIA2. It explains severe forms of osteoporosis but may not be as significant with the milder more common forms of the disease.

The Role of Genes in Osteoporosis

The presence of one or more genes that affect bone health is not a guarantee that a person will develop osteoporosis. However, the chances of developing osteoporosis are much greater especially when other factors such as nutritional deficiencies, lack of exercise and related diseases are present. Even if the loss of bone mineral density (BMD) is not as severe to  lead to osteoporosis, the bones may be sufficiently weakened where the risk of fracture is higher.

A person with a strong family history is therefore advised to take additional precautions to prevent osteoporosis particularly in women approaching menopause or both men and women as they get older. This includes eating a healthy diet, maintaining a regular regimen of weight bearing exercises and using nutritional supplements as prescribed by a doctor. Regular scans of bone mineral density is also essential to detect the disease in the early stages and intervene with osteoporosis drugs.