Reed Havlik is one of only 200 people worldwide with Vanishing White Matter (VWM) disease — a rare neurological condition that leads to rapid nerve deterioration.

Basic fright could kill him.

The 5-year-old Iowa boy has to avoid creepy movies and Halloween trick-or-treaters because a serious scare could cause pressure on his brain that could put him in a coma.

“We have to be really careful what we expose him to because he could be frightened to death,” his mom, Erika Havlik, told SWNS.

VWM disease has no cure or treatment — and the life expectancy of sufferers is around 10 years.

The genetic glitch, which affects one in every 40 million people, occurs when the body does not produce a substance that insulates the nerves of the body.

As a result, they disintegrate and disappear, and cells in the brain are particularly vulnerable. A knock to the head, a fever or a scare can speed up the disease’s progression.

Reed, who was diagnosed by specialists at the University of Iowa Children’s Hospital, in Iowa City in 2015, started having mobility issues at the age of 2.

An MRI scan showed the extent of his rare, terminal disease. As the white matter in Reed’s brain disintegrates, this will lead to organ failure.

His brain will be unable to communicate with his body and he will slowly be unable to talk, eat and eventually breathe.

Speaking further to SWNS, Erika described the day she found out about his diagnosis. “It was gut-wrenching. Sickening,” she said.

The mom added the family only celebrates Halloween on a small scale to avoid Reed being too stimulated.

He dressed up as Mickey Mouse Wednesday and his school threw a party where classmates wore costumes considered “not too scary.

“We are trying to give him the best life we possibly can and enjoy him whilst we can,” Erika said. “Our world has been altered completely. It’s been life-changing.”