What comes on top of your mind when you hear 'mutant', or 'genetic variants'? If you pictured the monstrous creature in the movie 'The Host', or the mutants with super powers in the movie 'X-men', this post will clear up the misconceptions on variants for you. If you thought that genetic variations lead to horrible results, or that you are a perfect being without any genetic variation, you were wrong.

In our past blog post titled, 'Human Genome Project: HGP', we explained about SNPs, the most common type of genetic variation amongst people.  Dimples, freckles, hair and eye colors are all affected or determined by SNPs. This means that we are all carriers of unique genetic variations.

In this blog post, learn about major types of genetic variations and how it is related to cancer susceptibility.

1.Germline variants inherited from parents

Germline variants are hereditary and are passed from parent to child. There are common genetic variations that lead to differences in looks between people, and uncommon genetic variations that influence the risk of developing certain disorders.

The gene variation BRCA1 or BRCA2, made known by a wider public thanks to Angelina Jolie's preventative mastectomy in 2013, are good examples of rare genetic variations that affect disease development. Research has found that females with these gene variations carry a 45-72% risk (55-72% for BRCA1 and 45-69% for BRCA2) of developing breast cancer. Uncommon gene variations are found generally in 1 or 2 genes, and if such variations are detected, a constant health monitoring is required.

The SNPs, which are a common type of genetic variation not only result in the different looks between people, but also play a role in affecting multifactorial diseases that are caused by a combination of genetic factors and environmental factors. In this case, several tens to hundreds of gene variations and environmental factors affect disease development.

2. Somatic variants acquired over the course of one's life

Some non-inherited variants occur over the course of one's life and are not passed to the next generation. These are called somatic variations and can lead to sporadic cancer, which is developed due to combinations of genetic variations and various environmental factors. Examples for such cases are people who develop lung cancer due to excessive smoking or skin cancer due to excessive exposure to UV rays. Genetic testing is generally used for selecting anti-cancer drugs or making prognostic judgements.

Cancer is a genetic disease that is developed when a genetic variant lead to uncontrollable growth of mutant cells or when the process of programmed cell death, or apoptosis, goes defect. In other words, cancer is developed 100% due to gene variations, whether germline or somatic.

Numerous efforts made by scientists to fight against cancer has resulted in successful measures to address the disease. Today, various types of genetic testing, such as genetic screening, prognostic and predictive tests are available to prevent cancer and monitor progressions.


Genoplan provides the predictive genetic testing results based on SNP data. The genetic testing is conducted by Genoplan Japan.