Lynch syndrome and genetic inheritance

Lynch syndrome is a genetic disorder that increases the likelihood of developing certain types of cancer, especially colorectal cancer. For this reason, Lynch disease has always been referred to as hereditary nonpolyposis colorectal cancer [1].

If you want to know more about Lynch syndrome, here we tell you its symptoms, which genes are involved in its development, and many other interesting facts about the disease that you probably did not know.

What are the main symptoms of Lynch disease?

An essential part of the symptoms of Lynch syndrome are similar to those of colorectal cancer, and some of those that may indicate the appearance of this disease could be [2]:

• Intestinal malabsorption
• Intestinal bleeding
• Abdominal pain.
• Constipation.
• Fatigue.
• Involuntary weight loss.
• Anxiety
• Depression
• Headache
• Nausea and vomiting.
• Attention deficit hyperactivity disorder.
• Abnormal behavior.
• Irritability.
• Seizures.

Colorectal cancer or glioblastoma, a type of brain cancer, are also considered symptoms of Lynch disease, whose primary lesion is usually a single colonic adenoma. This differentiates it from another form of colorectal cancer called familial adenomatous polyposis, characterized by multiple adenomas [3].

What is the relationship between Lynch syndrome and genetic inheritance?

Lynch syndrome is transmitted from parents to children in an autosomal dominant manner. The syndrome can develop if a child inherits a single copy of the mutated gene from one of their parents. The probability of this occurring when one of the parents has a copy of the mutation in one of these specific genes is 50%. If you want to learn more about the different forms of genetic inheritance and their relationship with hereditary diseases, you can do so here. 

We are composed of trillions of cells that grow and multiply in a regulated manner, known as cell proliferation. When a cell ages or shows some abnormality, it dies, called apoptosis. Both cell proliferation and apoptosis are highly regulated. However, the proliferation process can include errors (mutations) in the DNA of cells that cause them to begin to multiply in an uncontrolled manner and not die when they should. This is when oncological processes start. 

To prevent this, our system has a series of genes that are responsible for locating errors in the cells and fixing them.

In patients with Lynch Syndrome, these genes, known as “disparity repair genes,” don’t work well, so if an error occurs in cell multiplication, they may not act as they should. This would result in tumor initiation [1].

These genes, involved in the development of the disease, are MLH1, MSH2, MSH6, and PMS2 [4], and the inheritance of any of them mutated is the direct cause of Lynch syndrome. This does not imply that all children who inherit these genes from their parents will develop cancer but that their probability is higher than that of the general population.

How does diet influence Lynch Syndrome?

A study conducted by researchers at Wageningen University in the Netherlands, and published in the journal cancer, showed that the risk of cancer in people with Lynch syndrome doubles when they follow a diet based on consuming junk food [5].

On the other hand, the Mediterranean diet has been proven to be protective against cancer development thanks to the benefits associated with consuming foods rich in fiber, such as cereals, legumes, fruits, and vegetables [6].

Lynch syndrome and colorectal cancer prevention

Early detection of Lynch Syndrome could help prevent most colon or rectal cancer cases. The problem lies in the fact that being a poorly understood disease, it is underdiagnosed [7]. Moreover, as it’s so closely related to certain types of cancer, in many cases, the tumor is diagnosed before Lynch disease.

Knowing whether we are carriers of the mutated genes associated with Lynch disease is the first step in preventing various types of cancer, especially colorectal cancer. In addition, with this information, we can carry out more total periodic controls to detect precancerous lesions in time.

One of the methods to obtain this information that is nowadays available to the general population is genetic testing. At 24Genetics, we perform a genetic health test to determine if we have a mutation in the genes involved in the development of Lynch Syndrome.

We need a simple saliva sample to extract this data from your DNA. If you want to know everything that your genetic information can provide about your predisposition to suffer not only this disease, but hundreds of other ailments, purchase a health test on our website and find out as soon as possible.

Bibliography

[1] Lynch syndrome – Mayo Clinic Staff [published Sep. 2022; accessed Mar. 2023] Available at: https://www.mayoclinic.org/es-es/diseases-conditions/lynch-syndrome/symptoms-causes/syc-20374714

[2] What is Lynch syndrome | Symptoms, causes and how to treat the disease – La Vanguardia [published Jul. 2019; accessed Mar. 2023] Available at: https://www.lavanguardia.com/vida/salud/tipos-cancer/20190731/463800463457/sindrome-de-lynch-cancer-cancer-colorrectal-polipos-cancer-de-endometrio-cancer-de-utero.html

[3] Lynch syndrome – Minhhuyen Nguyen, MD, Fox Chase Cancer Center, Temple University [reviewed Mar. 2021; accessed Mar. 2023] Available at: https://www.msdmanuals.com/es-es/professional/trastornos-gastrointestinales/tumores-del-aparato-digestivo/s%C3%ADndrome-de-lynch

[4] Lynch syndrome – National Center for Advancing Translational Sciences [updated Apr. 2017; accessed Mar. 2023] Available from: https://rarediseases.info.nih.gov/espanol/12282/sindrome-de-lynch

[5] Lynch syndrome sufferers should avoid junk food – We Are Patients [published Dec. 2012; accessed Mar. 2023] Available at: https://www.somospacientes.com/noticias/avances/los-afectados-por-el-sindrome-de-lynch-deben-evitar-la-comida-basura/

[6] Living with Lynch syndrome – Dr. Francesc Balaguer Prunés and Dr. Judith Balmaña Gelpi [accessed Mar. 2023] Available at: https://www.seom.org/seomcms/images/stories/recursos/Vivir_Lynch.PDF

[7] People with Lynch syndrome have up to 82% chance of developing colon cancer – Sinc [published Mar. 2014; accessed Mar. 2023] Available at: https://www.agenciasinc.es/Noticias/Las-personas-con-sindrome-de-Lynch-tienen-hasta-un-82-de-probabilidades-de-padecer-cancer-de-colon