What Is Mitochondrial DNA Depletion Syndrome and Does Alfie Evans Have It?

At just under 2 years old, British infant Alfie Evans has captured worldwide attention. Evans has an undiagnosed neurological condition that has caused him to have seizures and lose the ability to walk, talk and eat on his own. His parents want to take him home, but the hospital wants to keep him there in palliative care.

It's unclear what condition Alfie has, which has destroyed more than 70 percent of the white matter in his brain. It's possible that Alfie has an exceedingly rare condition called mitochondrial DNA depletion syndrome, or MDDS. If so, he would be the 17th person in the world to be diagnosed with the disease, International Business Times reported.

An expert in childhood epilepsy has told a court that Alfie does not have any mitochondrial condition, according to U.K. news outlet Express. The expert, Helen Cross of Great Ormond Street Hospital, noted that an EEG scan showed no activity in Alfie's brain, except for producing seizures.

Still, many of Alfie's symptoms seem similar to ones that someone suffering from MDDS might have. Last year, at the same hospital, an infant named Charlie Grad was diagnosed with the condition and a similar controversy unfolded.

Alfie is unlikely to have MDDS, which is actually a group of conditions that can affect cells in different ways. It starts with the mitochondria, known as the "powerhouse of the cell." These organelles have their own DNA, and they convert oxygen into Adenosine Triphosphate, or ATP, which is integral to energy transfer in the cell.

According to Frontline Genomics, MDDS causes problems with the DNA in the mitochondria, making ATP production difficult. Someone without enough ATP may not have energy to move or talk much, and different organs in their body can deteriorate.

Another form of MDDS primarily affects the brain. This one first appears in infancy and can cause delays in learning, epilepsy, abnormal movements and loss of motor skills, creating symptoms similar to what Alfie is experiencing.

Doctors took Alfie off of life support three days ago, and surprisingly, he is still breathing on his own. His father suggests that Alfie could live for "months, possibly years" if treated.