Correction: An earlier version of this story incorrectly attributed a quotation about curriculum changes because a video played at the board meeting, which included the quotation, was mislabeled. The quotation should have been attributed to Adam Hiatt. The story has been updated.

The Fairfax County School Board has approved expanding the school system’s sex education curriculum to include teaching teenagers in grades 7 through 10 about gender identity and transgender issues.

The 10-to-2 vote Thursday night came amid shouts of anger and howls of frustration from a raucous crowd that largely stood in opposition to the curriculum changes.

The board’s decision centered on changes to the Family Life Education curriculum across all grades. The revisions included adding lessons on gender issues for middle and high school students. But some of those who opposed the changes questioned whether the revisions would trickle down to the lower grades.

Opponents also expressed concern that some of the revisions would move certain sensitive lessons out of the Family Life Education curriculum and into health class, which would remove parents’ ability to opt-out their children from learning the material. The health class is a required course; Family Life Education is not.

Andrea Lafferty, a Fairfax resident who is president of the Traditional Values Coalition, a conservative lobbying group, described the lesson changes as overreach by the School Board.

“Parents: Do you want your children in kindergarten to hear about same-sex marriage under the guise of families?” Lafferty asked.

Many in the crowd responded loudly: “No.”

The vote came a day before the U.S. Supreme Court voted 5 to 4 to allow gay marriage in all 50 states. In May, the School Board voted to expand the school system’s anti-discrimination policy to include protections for transgender students and staff.

In video testimony played at the meeting, Adam Hiatt said the curriculum changes should not be approved because they would go “against the teaching and faith of most major world religions.”

“Today’s version of the Nazi Germany description would be something like this: ‘First they came for traditional marriage, and I did not speak out because I wanted to be tolerant,” Hiatt said. “Then they came for the children in our schools, and I did not speak out. . . . Then they came for me, and there was no one left to speak for me.”

In response to vehement opposition that board members received via e-mail, the board appeared prepared to delay voting on the issue until July. Board member Patty Reed (Providence) offered a proposal to wait a month before voting on the new curriculum. Board member Elizabeth Schultz (Springfield) brought up a motion to table the matter until a later date.

At the last minute, the board moved ahead and overwhelmingly voted in support of the lesson changes, with Reed and Schultz the only votes against the new curriculum. In a slight concession, the board also voted to move some of the earlier proposed lessons back to their original place in the Family Life Education curriculum, allowing parental opt-outs for children.

Robert Rigby, adviser to the West Potomac High School student lesbian, gay, bisexual and transgender group, said he was proud that the School Board voted to approve the curriculum changes.

“The unruly crowd seemed to be trying to bully the School Board,” Rigby said.

“But the board showed the same courage in the face of those shouts that it showed in May, when it voted to add gender identity to the FCPS anti-discrimination policy.”