MUTYH-associated polyposis
| Classification according to ICD-10 | |
|---|---|
| D12 | Benign neoplasm of the colon, rectum, anal canal, and anus |
| D12.6 | Colon, unspecified Polyposis coli (hereditary) |
| ICD-10 online (WHO version 2019) | |
The MUTYH associated polyposis ( syn. MAP, MHY associated polyposis) is an autosomal - recessive inherited disease . It is an adenomatous polyposis disease. It was only discovered in 2002 and behaves clinically in a weakened form like familial adenomatous polyposis (FAP). It can therefore be assumed that it is similar to AFAP (attenuated FAP). In patients with a mild form of adenomatous familial polyposis, 15–20% MAP is diagnosed .
Symptoms
This disease leads to polyps in the colon which , if left untreated, can degenerate and lead to colon cancer . However, patients have so far shown a slower course of symptoms than patients with FAP. The diagnosis is usually made between the ages of 49 and 57, and colon cancer usually only occurs in untreated patients from the age of 50 or 60. Patients with MAP often show symptoms similar to those with FAP. These are mainly duodenal polyposis , duodenal carcinoma and osteomas .
root cause
Cause of the disease is a mutation of MUTYH - gene . This gene is located on chromosome 1 (1p34.3-p32.1), where it can be found on base pair 45.464.007 to base pair 45.475.152 and is composed of 16 coded exons . Usually the MUTYH gene is responsible for making a protein that repairs DNA . The base pairs usually only come in two forms: adenine with thymine and guanine with cytosine . As a result of oxidation , guanine and adenine can form a base pair. The protein produced by the MUTYH gene, MUTYH glycosylase , recognizes this error and repairs it. If there is a mutation in the MUTYH gene, the MUTYH glycosylase will not be produced. As a result, the DNA mutates and cancer can develop.
Inheritance
The inheritance is autosomal - recessive . The main consequence of this is that - in contrast to FAP - children can be genetically burdened without the parents showing any phenotypic signs. However, both parents must be carriers of the genetic make-up. Patients therefore rarely suspect that they are suffering from such a disease.
However, it should be mentioned that the inheritance means that siblings of a MAP patient have a 25% risk of also suffering from this hereditary disease . Children of a MAP patient are definitely carriers of this hereditary disease.
It was found that one percent of the population is a carrier of this hereditary disease. Children of a MAP patient therefore have a 0.5% probability ( homozygous genetic material and heterozygous genetic material; 1%, which is reduced to 0.5% due to two possible genotypes ) of developing MAP. Siblings and children should still have regular checkups.
literature
- Nils Rahner, Verena Steinke: Hereditary cancers. In: Dtsch Arztebl. 2008; 105 (41), pp. 706-713.
- Noel FCC de Miranda, Maartje Nielsen, Dina Pereira, Marjo van Puijenbroek, Hans F Vasen, Frederik J Hes, Tom van Wezel, Hans Morreau: MUTYH-associated polyposis carcinomas frequently lose HLA class I expression - a common event amongst DNA-repair- deficient colorectal cancers. In: The Journal of Pathology . 2009.
