A New York State Health Department investigation has found that a 6-year-old boy died last year after a hospital misdiagnosed a heart defect as acid reflux disease, Newsday reported Thursday.

William Gonzalez, of Mastic Beach, N.Y., died Sept. 11, 2007 at Stony Brook University Medical Center after it was discovered he had an enlarged heart.

According to a state report, the family had taken the boy to the hospital several times and he was treated for symptoms related to gastrointestinal reflux. Stony Brook was cited for failing to check for the enlarged heart until it was too late.

"We take this situation very seriously and we will work with the Department of Health to respond to the concerns identified in the report," hospital spokeswoman Lauren Sheprow told Newsday Wednesday. "We are thoroughly committed to delivering the highest quality of care."

The hospital is conducting its own investigation into the matter.

William's parents took him Brookhaven Memorial Hospital in August 2007 after he became ill, according to the report. He was diagnosed him with gastrointestinal reflux and referred to Stony Brook, where his parents took him on three separate occasions. It wasn't until his third visit that a chest X-ray was taken and revealed an enlarged heart. He died a day later.

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