MUTYH-associated Polyposis

By | June 8, 2022

MUTYH -associated polyposis is closely related to adenomatous familial polyposis and is caused by a genetic mutation. The patients suffer from multiple colonic polyps with a risk of degeneration. Regular colonoscopies are mandatory.

What is MUTYH-associated polyposis?

Polyp diseases in hollow organs are considered polyposis. Polyps are protuberances of the mucous membrane that occur more frequently in the gastrointestinal tract, among other things, and are referred to as gastrointestinal polyposis in this case. Especially in the context of gastrointestinal polyposis, there are different diseases with a genetic and hereditary basis. For krs – cardiorenal syndrome, please visit

One of them is the autosomal dominant hereditary MUTYH-associated polyposis, also known as MAP or MHY associated polyposis. The disease was only discovered in 2002 as an independent hereditary disease . It behaves as a clinically attenuated variant of familial adenomatous polyposis (FAP).

For this reason, since the discovery, researchers have assumed that the generalized course of the disease resembles that of AFAP. In addition, patients with a mild course of adenomatous familial polyposis are now diagnosed with MAP in up to 20 percent of all cases. Thus, in the broadest sense, MUTYH-associated polyposis can be viewed as the most favorable subvariant or close relative of adenomatous familial polyposis. According to studies, about one percent of the population are carriers of the disease.


The cause of MUTYH-associated polyposis lies in the genes. More specifically, it is a mutation in the MUTYH gene, located on chromosome 1 at gene locus 1p34.3-p32.1. The associated base pairs 45,464,007 to 45,475,152 carry 16 encoded exons. In a healthy organism, the superordinate MUTYH gene is involved in the production of a DNA-repairing protein.

This is the so-called MUTYH glycosylase, which monitors the formation of base pairs. The base pairs of the gene occur physiologically in two different forms and thus consist of adenine with thymine or guanine with cytosine. Upon oxidation, the base pair partners shift. For example, guanine can form a pair with adenine.

In healthy organisms, the DNA-repairing protein recognizes this event and repairs the mistake. If there is a mutation in the MUTYH gene, the MUTYH glycosylase loses its actual form and can no longer adequately fulfill its tasks. The inheritance of MUTYH-associated polyposis is autosomal recessive. Siblings of a patient therefore have a 25 percent risk of inheriting the polyp disease. Children of a patient definitely carry the hereditary disease.

Symptoms, Ailments & Signs

Patients with MUTYH-associated polyposis suffer from colon polyps. The polyps can appear in clusters of up to 100 pieces. However, in some cases only ten polyps were reported. Accompanying symptoms such as bleeding, flatulence, colic and pain in the rectal area are associated with polyps of the colon.

In addition, constipation, diarrhea and severe weight loss are common. Despite the sometimes considerable number of colon polyps, the course of the disease is estimated to be milder than familial adenomatous polyposis coli. Nevertheless, hyperplastic or serrated adenomas are often found among the multiple polyps.

This is associated with an increased risk of cancer. The median age for colon cancer is around 50 years for carriers of the disease. The carcinomas form preferentially in the proximal part of the intestine. Benign bone tumors in the sense of osteomas were also increasingly observed in the context of MUTYH-associated polyposis.

Diagnosis & course of disease

In most cases, the diagnosis of MUTYH-associated polyposis is made after the age of 50. In most cases, people see a doctor because of bleeding or persistent pain in the rectum. As part of the diagnosis, an endoscopy including a biopsy of the polyps is usually carried out.

A human genetic examination can round off the diagnosis. This procedure is primarily indicated for cases in which FAP has been ruled out despite many colonic polyps. A complete sequencing of the MUTYH gene is carried out as part of the human genetic analysis. Although patients with MUTYH-associated polyposis also have an increased risk of colorectal cancer, their prognosis is far more favorable compared to patients with FAP.


Those affected by this disease primarily suffer from problems in the intestines. This leads to the formation of so-called polyps, which ultimately lead to colic, flatulence and pain in the intestines and stomach. It is not uncommon for those affected to also suffer from diarrhea or constipation and thus a severely reduced quality of life. Furthermore, long-term problems with the stomach and intestines can lead to psychological problems or depression.

The risk of cancer is also significantly increased by this disease, so that patients are dependent on various check-ups. When not sailing, patients with this disease consume less food, resulting in deficiency symptoms or underweight. Above all, the risk of colon cancer increases enormously as a result of this disease.

Treatment is usually with the help of medication. There are no particular complications. Through various regular examinations and checks, further illnesses can be avoided or detected at an early stage. If the person concerned is underweight or suffers from a deficiency, the missing nutrients must be administered through an infusion.

When should you go to the doctor?

Irregularities in the area of ​​​​the intestine should be observed by the person concerned. If they last for several days or increase, they should be checked out by a doctor. If you have flatulence, constipation or diarrhea, you should consult a doctor. If there are intestinal noises, a feeling of pressure or pain in the abdomen, there is a disorder that must be treated medically so that no further complications follow.

A loss of appetite, an unwanted decrease in body weight and a feeling of internal dryness are signs that require action. A decrease in strength, sleep disturbances or a general feeling of illness should be examined and treated. If everyday professional and private obligations can no longer be met, the person concerned should seek the help of a doctor.

If bleeding occurs during bowel movements, itching occurs or open wounds develop on the anus, a doctor’s visit is advisable. Pathogens can penetrate the organism and lead to further diseases. In addition, sterile wound care is necessary to prevent blood poisoning. A doctor should be consulted if skin changes, a burning sensation in the anus, fever, malaise or internal weakness occur.

Treatment & Therapy

A causal therapy is not available for patients with MAP because the disease is genetic and is due to DNA damage. Significant advances in gene therapy can now be observed, so that a gene therapy causal therapy approach cannot be ruled out within the next few decades.

However, since gene therapy approaches are not yet in the clinical phase, patients with MUTYH-associated polyposis have so far only been treated symptomatically. The focus of symptomatic treatment is less on actual therapy and more on regular monitoring. Check-ups at frequent intervals are mandatory because of the increased risk of cancer and should take place from the age of 30 at the latest.

Biopsies are taken from hyperplastic or otherwise conspicuous polyps as part of the check-ups. Particularly conspicuous representatives are removed by resection if necessary in order to reduce the risk of degeneration. In addition to the check-ups, patients with the disease have access to symptomatic pain therapy, which usually corresponds to drug treatment.

If malnutrition occurs due to persistent diarrhea, the respective deficiency is compensated with intravenous infusions.

Outlook & Forecast

MUTYH-associated polyposis (MAP) apparently increases the risk of developing colorectal cancer due to genetic factors. Therefore, the long-term prognosis is not so positive. Accurate and comprehensive diagnostics are therefore important in order to be able to clearly differentiate MUTYH-associated polyposis as such from similar hereditary gastrointestinal polyposis syndromes. Second, adequate therapy and long-term monitoring of colon polyps through regular examinations of the intestinal tract are useful.

The risk of degeneration with this type of intestinal polyp is significantly higher than with other intestinal diseases. For this reason, MUTYH-associated polyposis requires regular colonoscopies. This allows any developing colon cancer to be detected as early as possible. Compared to the so-called FAP polyposis, the prognosis for people with confirmed MUTYH-associated polyposis is significantly better. But the prospects are still bad overall.

In this respect it can be said that a MUTYH-associated polyposis can involve long-term risks of colon cancer. However, these risks can be minimized with regular colonoscopies and genetic determination of polyp type. In this case, early detection is a safe tool that promotes healing in the event of a diagnosis of colorectal cancer.

It is also important that patients with MUTYH-associated polyposis pay attention to their nutritional values. If you have constant intestinal problems, you can easily develop serious nutrient deficiencies. If necessary, infusion treatments are necessary to ensure the nutrient supply.


Molecular genetic analyzes are a preventive step in the context of MAP. Above all, people with a corresponding family history learn from the analyzes whether they are homozygous carriers of the MUTYH gene mutation. If this is the case, regular colonoscopies from the age of 30 serve to prevent cancer.


Due to the disease, those affected suffer from severe complications and serious symptoms. Therefore, with this disease, a doctor must be consulted as soon as the first symptoms and signs appear, so that the symptoms do not worsen further. If the disease is not treated, it can lead to the death of the affected person in the worst case.

Those affected primarily suffer from severe abdominal pain. This leads to diarrhea, constipation and generally severe abdominal pain. Many patients also suffer from flatulence and even bloody diarrhea. Persistent abdominal pain can also lead to significant weight loss. The risk of cancer also increases due to the symptoms, which is why many patients develop colon cancer.

The symptoms themselves can lead to depression or other strong psychological upsets in some of those affected, so that they are also dependent on psychological treatment. The further course depends heavily on the exact severity of the symptoms. The life expectancy of those affected may also be reduced due to the disease.

You can do that yourself

Patients with MUTYH-associated polyposis suffer from unpleasant symptoms due to the disease of the colon, which reduces the quality of life. In their own interest, those affected regularly visit various specialists and undergo the preventive examinations offered in order to diagnose any cancer diseases in good time. Due to the uncertainty about the course of the disease and the symptoms themselves, some patients develop anxiety disorders or even depression. Then it is urgently appropriate to consult a psychologist. The psychotherapist supports the patient in dealing with the physical illness and strengthens mental stability.

If the doctor prescribes medication, the person concerned must take it exactly as prescribed by the doctor. The patients often suffer from colic, diarrhea or constipation, which also have a negative impact on everyday life and make it difficult to participate in social life. It is therefore urgently indicated to consult a medical nutritionist. He develops an individual diet plan for the patient in order to reduce the symptoms and to ensure the often impaired supply of nutrients.

It is also helpful if those affected refrain from smoking and drinking alcoholic beverages. This saves the organism from processing the corresponding toxins and at best has a beneficial effect on the course of the disease.

MUTYH-associated Polyposis