Genetics play a huge role in health and disease development. Certain genetic mutations are associated with the development of specific conditions; for example, DMD gene mutations cause Duchenne muscular dystrophy. Now, researchers also know that certain genetic mutations also increase the susceptibility to different infections. According to Medical XPress, researchers recently suggested that MX1 mutations increase susceptibility for H7N9 avian flu. Interested in learning more? Take a look at the research published in Science.
H7N9 Avian Flu
So what exactly is H7N9 avian flu? According to the Centers for Disease Control and Prevention (CDC), H7N9 avian flu first appeared in China in 2013, although cases have slowed down since 2017. The CDC explains that infection occurs:
after exposure to infected poultry or contaminated environments.
Initially, this was a novel avian flu, meaning it had never been seen in humans before. Medical News Today also explains that, within the first four H7N9 avian flu epidemics in China, an estimated 40% of patients died. The illness manifests as severe respiratory illness (such as pneumonia, acute respiratory distress syndrome, or difficulty breathing). Additional signs and symptoms include:
- Fever
- Headache
- Cough
- Sore throat
- Muscle aches
- Nausea and vomiting
- Abdominal pain
- Diarrhea
The Research
Now, researchers sought to understand how and why certain people are susceptible to H7N9 avian flu while others are not. Although the virus is associated with contaminated poultry, only 7% of those infected were poultry workers, suggesting that susceptibility plays a huge role in infection. Because of that, researchers believed there was some sort of underlying genetic cause.
To begin, the researchers collected and analyzed tissue samples from 336 individuals. Of these, 220 (65.5%) had been infected with H7N9 bird flu. The remaining 116 individuals (34.5%) were poultry workers who had not been infected. After collecting these samples, researchers performed genetic sequencing. Learn more about genetic sequencing. Through this, researchers determined that:
- The MX1 gene encodes for MxA, a type of antiviral protein. When patients have MX1 gene mutations, their bodies are less likely to produce this protein, which prevents infections.
- Of the 116 patients who had not been infected with avian flu, approximately 0% of them had MX1 gene mutations. Alternately, 10% of those who had been infected had these genetic mutations.
- Altogether, researchers found multiple mutations. Only three were not linked to poor MxA activity.
