Mutation in NAMPT Gene Found to Cause Rare Neurological Disease

An international research team, led by Shinghua Ding at the University of Missouri, has identified a previously unknown genetic disease that affects movement and muscle control.

The disease - called Mutation in NAMPT Axonopathy (MINA) syndrome - causes damage to motor neurons, the nerve cells that send signals from the brain and spinal cord to muscles. It's the result of a rare genetic mutation in a critical protein known as NAMPT, which helps the body's cells make and use energy. When this protein doesn't work as it should, cells can't produce enough energy to stay healthy.

Over time, this lack of energy causes the cells to weaken and die, and leads to symptoms such as muscle weakness, loss of coordination and foot deformities - which can worsen over time. In severe cases, patients may eventually need a wheelchair.

Although this mutation is found in every cell in the body, it seems to primarily affect motor neurons. We believe nerve cells are especially vulnerable to this condition because they have long nerve fibers and need a lot of energy to send signals that control movement."

Shinghua Ding, Professor, Mizzou's College of Engineering

From Research to Discovery

This discovery builds on years of foundational research by Ding and his collaborators.

In 2017, Ding published a landmark study showing that NAMPT is critical for maintaining healthy neurons. He found that a lack of NAMPT in nerve cells leads to paralysis and symptoms similar to ALS, a well-known motor neuron disease.

That finding caught the attention of a medical geneticist in Europe, who later reached out to Ding after seeing two patients with unexplained muscle weakness and coordination issues. The doctor asked if Ding's team could investigate.

Ding and collaborators studied the patients' cells and a mouse model. They found both patients had the same NAMPT mutation, confirming it was the cause of the disease. Interestingly, the mice carrying the mutation did not show visible symptoms, but their nerve cells displayed the same internal problems seen in the human cells.

"This shows why studying patient cells is so important," Ding said. "Animal models can point us in the right direction, but human cells reveal what's really happening in people."

While there's no cure yet for MINA syndrome, researchers are already testing ways to boost energy levels in affected nerve cells.

This research marks a significant step forward in understanding rare genetic diseases and how disruptions in cellular energy metabolism can affect nerve health. It also demonstrates how basic scientific research can lead to discoveries that have direct implications for patients living with rare, unexplained conditions.

The study, "A sensory and motor neuropathy caused by a genetic variant of NAMPT" was published in the journal Science Advances.