Cancer starts when cells in some part of the body start to grow uncontrollably. And since the growth is different from normal cell growth, cancer cells continue to grow and form abnormal cells. The reason behind such behavior of cells is damaged DNA. In cancer cells, the damaged DNA does not get repaired, and the cell doesn’t end like it should. Instead, this cell goes on making new cells that the body does not require. Sometimes when damaged DNA is passed along the generation and causes cancer, it is referred to as inherited cancer.
DNA and cancers
Every cell in our body has genes that we were born with and cancer is a disease of abnormal gene functionality. While genes contain information on various vital functions of the body, it also affects your chances of getting a cancer.
Modes of inheritance
An abnormal change in the genes is referred as mutation. There are 2 types of mutations – inherited and somatic (acquired). Depending on the seriousness and the type of affect, inherited cancers can be categorized into different modes.
DNA and cancers
Every cell in our body has genes that we were born with and cancer is a disease of abnormal gene functionality. While genes contain information on various vital functions of the body, it also affects your chances of getting a cancer.
Modes of inheritance
An abnormal change in the genes is referred as mutation. There are 2 types of mutations – inherited and somatic (acquired). Depending on the seriousness and the type of affect, inherited cancers can be categorized into different modes.
- Autosomal dominant inheritance : It affects both males and females in all generation. Examples : Huntington's disease, Achondroplasia and Neurofibromitosis.
- Autosomal recessive inheritance : Offspring of two parents who carry cancers can be affected by this mode of inheritance. Generally, it is only seen in one generation. Example : Wilson's disease, PKU and Cystic fibrosis.
- X-linked recessive inheritance : Male offspring of heterozygous carrier (mother) can be affected from such inheritance. Usually, there is no father to son transmission and all female offspring of the affected male will be carriers. Example : Hemophilia A and B and Duchenne muscular dystrophy.
- X-linked dominant inheritance : Similar to x-linked recessive mode, all daughters of male carriers are affected in this mode of inheritance as well. While there is no male to male transmission of damaged genes here, both males and females can equally be affected from such inheritance.
- Mitochondrial : Such inheritance is only possible through mother and all offspring of affected mother are subjected to it.
Inherited cancer syndromes
There are various inherited cancer syndromes which can run across families. Some of them are :
- Hereditary breast and ovarian cancer syndrome
- Lynch syndrome
- Malignant malinoma
- Hereditary diffused gastric cancer
- Paraganglioma Syndromes
- Cowden Syndrome (PTEN)
- Von Hippel Lindau (VHL)
- Neurofibromatosis type 1 and type 2 (NF1 and NF2)
- Juvenile Polyposis
- Li-Fraumeni Syndrome (TP53)
- Peutz-Jeghers