Meningioma and DNA Heredity

Meningiomas are usually benign tumors of the lining of the brain and spinal cord. While they are typically asymptomatic, they can cause symptoms and be dangerous in certain cases. New DNA research is revealing a hereditary factor in about half of them. Here is what you need to know about getting your DNA tested.

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Recently my wife was diagnosed with a meningioma tumor. Today, we are so thankful that after the first MRI, the doctors could tell that it was benign. This type tumor is formed in the membrane layers around the brain (also known as the meninges). In some cases, there may not be symptoms. As many as one to two percent of autopsies reveal meningiomas the patients did not know were present when they were alive because they cause no symptoms. When symptoms do occur, as in the case with my wife, the type depends on the size and location of the tumor. Symptoms can range from occasional seizures, more frequent seizures, difficulty talking, weakness on one side, dementia, and loss of bladder control. The severity also depends on the tumor’s size and location, and symptoms may range from mild to severe.

A gracious gift from our Lord… The tumor was removed and she is recovering quickly from the earlier symptoms.

Rejoice always; pray without ceasing; in everything give thanks; for this is God’s will for you in Christ Jesus. – 1 Thessalonians 5:16-18 (NASB)

If you’re interested, here are some of my findings from my brief study on meningioma tumors and DNA testing.

What Are the Risk Factors?

Risk factors for this type of tumor can include exposure to ionizing radiation (such as dental x-rays, a leading source of this radiation), neurofibromatosis type two, obesity, and a family history of them. They do not appear to be related to cell phone use as some consider. Diagnosis is typically made by medical imaging (MRI).

If no symptoms are present, the only type of treatment that may be necessary is observation. When there are no symptoms, the diagnosis is usually made by accident, when imaging for something else. When there are symptoms, they can usually be cured by surgery to remove the tumor. If the entire tumor is removed, there is a less than twenty percent chance of it recurring.

If surgery is not possible due to the location, health of the patient, or some other reason, radiosurgery can be used and has been found to be helpful. Since ninety percent of meningiomas are benign, chemotherapy has not been found to be useful. Surgery or radiosurgery are the best options for a cure when symptoms are present and the tumor is in its usually benign state.

Around one per one thousand people are affected by this condition in the United States, and onset is usually in adults over the age of fifty. Women are affected twice as often as men, and this type of tumor represents about thirty percent of all types of tumor in this area of the body. Scientists and medical professionals have known about them since at least 1614 when the first recorded description of one was written down by Felix Plater.

Felix Plater

In 1614 the first recorded description of a meningioma was written down by Felix Plater.

Most cases of meningioma are sporadic and random, while others seem to have a hereditary component. Outside of the hereditary factor, exposure to radiation, especially around the scalp, seems to increase the risk, and people who survived Hiroshima, as well as those who had a large number of dental x-rays decades ago (when the amount of radiation used was higher than it is today) have reported larger than average incidences of this condition. Those with excess body fat also seem to be at an increased risk for it.

Known Genetic Components

There is definitely a genetic component in a number of these cases. In fact, recent studies have shown that about fifty percent of cases involve a genetic component. This component is a mutation on the neurofibromatosis type 2 gene on chromosome 22q.

One-quarter of cases involve a mutation on the TRAF7 gene. A mutation on this gene, as well as on the KLF4, AKT1, and SMO genes usually result in a benign meningioma at the base of the skull. A mutation on the neurofibromatosis type 2 gene usually results in a meningioma in the cerebellar and cerebral hemispheres.

While the vast majority of meningiomas are benign, they can also be atypical (seven to eight percent) or anaplastic/malignant (two to three percent). With treatment, the average survival rate for anaplastic ones is three and a third years, while the average survival rate for atypical ones is eleven and nine-tenths years. Average relapse-free periods for anaplastic ones is a little over two and a half years, while the relapse-free period for atypical ones is, on average, eleven and a half years.

Though most meningiomas are benign and harmless, they can grow big enough to cause severe symptoms requiring surgery, or even to be life-threatening; they can also appear in locations that make them dangerous. There is also a benign “petroclival” type of meningioma that is typically fatal if it is not treated, due to its location. There was no good treatment for it until the 1970s. While there are treatments available now, this particular type of benign meningioma remains challenging to treat and outcomes, while not always fatal like they usually were before the 1970s, are still great for most patients.

While meningiomas are more common in women than in men, men are more likely to get the overwhelmingly rare aplastic/malignant ones. They are more common after age fifty, and the risk for developing one increases the older one becomes. These types of tumors have been observed across all cultures in the world, both Western and Eastern.

Can DNA Research Help?

Recent research has placed a stronger emphasis on the hereditary nature of meningiomas. Umea University in Sweden has identified an inherited susceptibility to them in some people. That discovery led to the discovery of the DNA genetic components involved in hereditary meningiomas. The research is interesting because it does prove there is a family heritability of them, and also allows researchers to examine the hereditary factor against such things as environmental factors, ionizing radiation exposure, obesity, and other known risk factors for them. This will give scientists a much better picture of the cause, treatment, and prevention of this condition.

Once more research is done into these new findings, it will become much easier to successfully treat those with hereditary meningiomas, and even to prevent them in the first place. Outcomes will be much better for those with aplastic ones, atypical ones, and benign ones with bad placement or symptoms. In time, those genes may be able to be edited to remove the mutations and take away the hereditary factor altogether. Then, they will gradually become less dangerous, when danger is present, and then a thing of the past altogether. With the future of DNA research, meningiomas may become extinct.


About the author

Ancestral Findings

Will founded Ancestral Findings in 1995 and has been involved in genealogy research for over 24 years. The excitement begin when he started investigating the meaning of his Moneymaker surname.