A virus lying dormant within human DNA for several million years may spring back to life and cause the crippling disease, amyotrophic lateral sclerosis (ALS), a Thursday published report stated.

Researchers at the National Institutes of Health, who discovered the relationship between genetic fragments of the dormant virus known as human endogenous retrovirus type K (HERV-K), think that giving patients antiretroviral therapy — drugs similar to the ones used to treat human immunodeficiency virus (HIV) — may also help those who suffer from ALS.

Lead author of the study, Dr. Avindra Nath, is typically an HIV researcher but in 2006, he treated an HIV patient that led to his curiosity about ALS.

Aside from being HIV positive, his patient also carried a disorder that resembles ALS. When Nath gave this particular patient the standard combination of antiretroviral drugs for HIV infection, he discovered that the patient's ALS-like symptoms improved.

In 2011, Nath and colleagues said that brain tissues from patients who died from ALS were found to have elevated levels of the virus. Additional tests showed that the virus has awakened.

Nath and team conducted animal tests, introducing genes from the virus to mice and found that the mice developed a disease much like ALS.

It remains unclear as what caused the virus to be activated, but chemicals and physical trauma may increase the risk of developing the disease.

The team of scientists is now planning to recruit individuals who suffer from ALS and at the same time have HERV-K activity.

The scientists will give them HIV treatment to see if it can reduce the levels of HERV-K.

Currently, no effective treatment exists for ALS, which affects an estimated 6,400 people in the United States each year.

The fatal neurodegenerative disease affects neurons in the brain and spinal cord that consequently affect muscle controls such as walking, talking, and breathing.