The National Institute of Health (NIH) has created a new approach to diagnosing and treating methylmalonic acidemia (MMA), a rare genetic disorder that stops the body from metabolizing fats and proteins correctly. They have created a breath test that is meant to not only diagnose and assess the severity of one’s condition but decide which treatment would be most beneficial. The full study investigating this new diagnostic method was published in Genetics in Medicine.
About MMA
Methylmalonic acidemia is a form of organic acidemias that stops the body from properly metabolizing certain fats and proteins, allowing them to accumulate over time. Symptom onset typically occurs within the first few months of life and causes effects like:
- Developmental delays
- Vomiting
- Respiratory distress
- Drowsiness
- Seizures
- Coma
- Weak muscle tone
- Enlarged liver
- Dehydration
- Acidosis
- Low blood sugar
- Low levels of platelets and red/white blood cells
- Very high levels of ammonia, ketone bodies, and/or methylmalonic acid in the urine and blood
All of these symptoms are the result of a mutation in one of five genes: MCEE, MMAA, MUT, MMAB, and MMADHC, all of which are inherited in an autosomal recessive pattern. When these genes are altered, the enzyme production within the body is impacted and fewer enzymes are produced. Therefore, the body cannot properly break down all of the materials that it needs to, leading to the accumulation of proteins and fats. Treatment consists of a specialized diet that is low in protein and avoids certain amino acids, antibiotics, and various medications to control symptoms. In severe cases, an organ transplant may be necessary.
Breath Test for MMA
Many rare diseases require creative solutions when it comes to research, diagnosis, and treatment. MMA is no different. NIH researchers looked at the disorder from a different angle when working on this project; instead of trying to track levels of metabolic proteins, they turned towards the actual process of metabolism. They knew that MMA interrupts the normal oxidation process within the metabolism, so they created a breath test that is able to quantify the amount of carbon dioxide that one exhales.
In order to discover these things, participants in a study were given some form (liquid or feeding tube) of a common food additive with a heavier form of carbon. This made it possible for the researchers to track the metabolic process within the MMA patients’ bodies. Upon examination, they found:
- MMA patients who have undergone an organ transplant, along with healthy individuals, exhaled higher levels of the heavier form of carbon
- These levels can tell doctors if an MMA patient is stable enough or suitable for an organ transplant
Looking Forward
The next step for research into the test is to evaluate its effectiveness in patients who have been treated with gene therapies or mRNA treatments. Additionally, they hope to make the breath test widely available.
Find the source article here.
