(Reuters) – A 5-year old boy has died in New York from a rare inflammatory syndrome believed to be linked to the novel coronavirus, highlighting a potential new risk for children in the pandemic, Governor Andrew Cuomo said on Friday.

Cuomo told a daily briefing that the boy died in New York City on Thursday and that health officials were looking at other deaths involving children under similar circumstances to see if there is a link to COVID-19, the disease caused by the virus.

“There has been at least one fatality because of this and there may be others that are now under investigation,” Cuomo said. “This is every parents’ nightmare, right, that your child may actually be affected by this virus.”

Cases of rare, life-threatening inflammatory illnesses in children associated with exposure to COVID-19 were first reported in Britain, Italy and Spain, but doctors in the United States are starting to report clusters of kids with the disorder, which can attack multiple organs, impair heart function and weaken heart arteries.

Dr. Sean O’Leary, a pediatric infectious disease expert at Children’s Hospital Colorado who serves on the American Academy of Pediatrics committee on infectious disease, said he believes the New York case is the first reported death from this syndrome in the United States.

The syndrome shares symptoms with toxic shock and Kawasaki disease, which is associated with fever, skin rashes, swelling of glands, and in severe cases, inflammation of arteries of the heart. Scientists are still trying to determine whether the syndrome is linked with the new coronavirus because not all children with it have tested positive for the virus.

Cuomo said New York’s health department, which on Wednesday issued an advisory to healthcare providers about the so-called pediatric multi-system inflammatory syndrome, were reviewing 73 cases with children showing similar symptoms across the state.

“While rare, we are seeing some cases where children affected with the COVID virus can become ill with symptoms similar to the Kawasaki disease or toxic shock-like syndrome that literally causes inflammation in their blood vessels,” the governor said.

This emerging syndrome, which may occur days to weeks after a COVID-19 illness, reflects the surprising ways that this entirely new coronavirus infects and sickens its human hosts.

In Westchester County, a suburb of Manhattan, officials said on Friday that they were reviewing the recent death of another child that was possibly related to the syndrome and COVID-19 at the Maria Fareri Children’s Hospital in Valhalla, New York.

“In these early stages, we cannot say with certainty whether this was specifically related to COVID-19, and not to underlying medical issues,” the Westchester Medical Center Health Network, which counts the hospital in its network, said in a statement.

If the syndrome grows in prevelance it would shake a prior assumption that children by and large did not have to worry about COVID-19, Cuomo said.

“This would be really painful news and would open up an entirely different chapter,” he said. “I can’t tell you how many people I spoke to who took peace and solace in the fact that children were not getting infected.”

In neighboring New Jersey, a child was among the 162 COVID-19 fatalities reported on Friday by state Health Commissioner Judith Persichilli. Speaking at a briefing, Persichilli declined to provide any details about the child to protect the privacy of the family other than to say that the child had “an underlying medical condition.”