The family of a 12-year-old boy who is brain dead is fighting a hospital's attempt to have him taken off life support, arguing that their faith does not define death as the cessation of brain function alone.

The boy's parents, who are Orthodox Jews, have retained a lawyer who says the boy's circulatory and respiratory systems are functioning, although with mechanical and other assistance.

Motl Brody of Brooklyn, N.Y., was diagnosed with severe brain cancer and has been at Children's National Medical Center for six months. Doctors pronounced him dead Tuesday after tests found no brain activity.

The hospital is seeking a court order that affirms its plan to disconnect the boy from a ventilator and to discontinue intravenous medications that keep his heart beating.

The parents' attorney says doing so would infringe upon religious freedom.

"Under Jewish law and their faith, there is no such thing as brain death," attorney Jeffrey Zuckerman told The Washington Post. "Their religious beliefs are entitled to respect."

Under District of Columbia law, doctors can declare patients dead if there is no brain activity. The case is awaiting a ruling from a D.C. Superior Court judge.

"This child has ceased to exist by every medical definition," Sophia Smith, one of the boy's physicians, wrote in court papers, adding that she and her staff members are "distraught at what is providing futile care to the earthly remains of a former life."

In court papers, the hospital's lawyers wrote that doctors have no choice but to stop life support or risk fines and other sanctions. They added that the hospital tried to find other facilities to take the boy but that none would admit him because he is brain-dead.