Most of the 200 students of Our Lady of Hope School in Potomac Falls donned hats Sept. 12 — some funny, most just regular — for “Hats on for Joey Day,” a show of support for third-grader Joey Angel. At an early morning assembly they gathered in the school gym for a picture and a prayer by Father P. William Saunders, pastor, who asked for God’s blessing on the 8-year-old with a serious blood disorder. Noting that it was the feast of the Most Holy Name of the Blessed Virgin Mary, Father Saunders led the students in a Hail Mary.

That evening, Joey underwent a procedure at Children’s National Medical Center in Washington that took bone marrow from an anonymous 49-year-old woman and transplanted it into his body. In about five weeks, if the chemotherapy he’s been taking prevents his body from rejecting the donated marrow, Joey will be considered cured of a mysterious blood disease that he has had since birth.

The procedure was expected to take just 30 minutes, instead it lasted more than 2 hours. But Joey’s mother, Janel Giambrone, said it went well.

The donor was an unrelated match, which means a direct relative was not the donor. There were no compatible candidates among relatives.

The anonymous woman came into the transplant network recently and was a very close match. Giambrone said it was a miracle.

She said her son does not have a clear diagnosis of a disease; his condition is a mystery. All tests for most known blood diseases have turned up negative. He is being treated for severe aplastic anemia, which Giambrone said is “an emptying of the bone marrow,” and this transplant can mean a normal life for her son.

From birth, Joey has been treated for low platelets — a normal count is 160 to 300, his was 25. Giambrone said at times it dropped to as low as two. He’s been in and out of hospitals, including the Mayo Clinic in Rochester, Minn., his entire life.

Joey hasn’t been at school since last November because of his weakened immune system. However, he did return to school briefly for his first Communion.

On hat day, Joey’s brothers, Jeremy, 11, and John Paul, 10, wore Angry Birds knit caps.

“I think it’s pretty cool,” Jeremy said about the outpouring of support for his little brother.

Even the brothers were separated from Joey when he stared chemo a week before the transplant.

“We Skype two or three times a day,” said John Paul, referring to the video hookup they use to communicate with their brother while he’s in the hospital.

Parishioners Lisa Kelly and Jennifer McCabe, members of the PTO service committee, helped organize “Hats on for Joey Day.” The group sponsors an event once a month to teach children the importance of service.

The day before the transplant, Giambrone wrote on her son’s Caring Bridge page, “Tomorrow is ‘day zero’ kind of like a new birthday.”

Joey’s Caring Bridge page has more than 2,000 visits, many leaving tributes in his honor.

“It’s absolutely amazing,” Giambrone said about the outpouring of support from Our Lady of Hope School and

others. “It’s humbling to receive the blessing of love.”

Joey’s mother said that he’s feeling the effects of the chemo and has good and bad spells. His hair is expected to fall out this week or next. He has been able to receive holy Communion in his hospital room.