Is Breast Cancer Inherited From the Mother or the Father?

Everyone possesses the 'breast cancer gene' syndrome, even if we all share the same genes. Understanding the intricacies of genetics can help debunk misconceptions and promote informed health decisions. This article explores whether breast cancer is inherited from the mother or father, focusing particularly on the BRCA1 and BRCA2 genes.

The Basics of Genetics and Cancer

Certainly, everyone has the same set of genes, but these genes consist of numerous varying locations, each coding for a specific substance the human body requires. Cancer, including breast cancer, can occur due to a misspelling or incorrect code at a particular location on a gene, resulting in the production of a substance that fails to perform its intended function.

Imagine a cookbook with multiple recipes. While all cookbooks have the same ingredients and steps, some may have slightly different instructions, affecting the final product. Similarly, while all humans have the same genes, the specific alleles (variations of a gene) can differ, influencing the potential for developing certain diseases like breast cancer.

Exploring the BRCA1 and BRCA2 Genes

When discussing the 'breast cancer gene,' it typically refers to BRCA1 or BRCA2. Every person carries both of these genes, but the specific allele (form of the gene) can influence one's susceptibility to breast cancer. For instance, the gene that determines the color of a pea plant can result in either green or yellow peas, with each pea plant having the gene but some carrying a characteristic that results in yellow peas. Similarly, an individual may inherit an allele that increases their risk of breast cancer from either parent.

It is crucial to understand, however, that breast cancer is a complex disease, not exclusively caused by the presence of the BRCA1 or BRCA2 gene. Many other genes can influence the risk, and even if an individual carries a high-risk allele, it does not guarantee the development of cancer. Other factors, such as lifestyle and environmental influences, also play a significant role.

Inheritance and Risk

The risk of inheriting breast cancer is not confined to either the mother or the father. Both parents can pass on alleles that increase the likelihood of developing the disease. However, hereditary cancers account for less than 5% of all cancers. In families with the BRCA gene, one might observe first-degree relatives (parents, siblings, children) developing cancers at significantly younger ages than typical. For example, most breast cancer cases are diagnosed after the age of 50, but if a first-degree relative was diagnosed at 35, it might be a cause for concern and warrant further testing.

It is also important to recognize that cancer is largely associated with age. As people live longer, it is common for family members to have a history of cancer. This does not necessarily indicate a family risk. For instance, in my family, only one of my grandparents lived to a very old age, and it is impossible to determine if they might have had cancer. The one who lived to 95 was cancer-free, but my parents both developed cancer in their 70s – one from smoking and the other from an experimental radiation treatment for prostate cancer that likely led to leukemia. My personal risk is the same as the general population, with a slightly higher risk for females who may have a normal diet and slightly plump body type.

Summary and Conclusion

While there is a genetic component to breast cancer, particularly through mutations in the BRCA1 and BRCA2 genes, inheritance from the mother or the father does not determine the likelihood of developing the disease. Hereditary factors account for a small percentage of overall cases, and the majority of cancer cases are influenced by a combination of genetic and environmental factors. Awareness and regular screening can help in early detection and management of potential risks.