TOLEDO, Ohio -- A judge's decision appointing a guardian to make medical decisions for an Amish girl after her parents stopped her chemotherapy violated their constitutional rights and could affect the rights of other parents to make their own medical choices, the family's attorney said in a court filing.

The lawyer for the family of the girl, Sarah Hershberger, wants a state appeals court to overturn the order assigning the guardian.

Sarah and her parents have been in hiding to avoid resuming chemotherapy since the guardian was appointed in October. They won't return to their farm in northeastern Ohio until the guardian is removed, their attorney has said.

The guardian, Maria Schimer, an attorney who's also a registered nurse, also no longer wants to force 11-year-old Sarah to undergo chemotherapy for her leukemia because she can't contact the girl or her parents.

But she also said that an Ohio appeals court should not grant the Hershberger family's request to reverse the ruling that made her the girl's guardian because the family didn't raise the issue of their constitutional rights being violated in the trial court.

The lawyer for Sarah's family disagreed, responding in a filing on Friday with the Ninth District Court of Appeals in Akron that "fundamental and constitutional rights that implicate matters of great public importance and constitutional significance cannot be forfeited."

Allowing the guardian to overrule the parents "affects the parental rights and health care freedom of all Ohio parents," wrote Maurice Thompson, who leads the libertarian 1851 Center for constitutional Law in Ohio.

"Any parent could have significant decisions second-guessed, any parent could lose the right to choose the doctor, hospital and course of medical treatment of their choice," the family's attorney said.

The Hershbergers decided this past summer to halt the cancer treatments because they feared the chemotherapy could end up killing the girl. Doctors at Akron Children's Hospital believe Sarah's leukemia is treatable, but they said in August that she will die within a year without chemotherapy.

The Hershbergers shun many facets of modern life and are deeply religious. They have said they stopped chemotherapy not for religious reasons but because it was making Sarah too sick. Instead, they decided to use natural medicines, such as herbs and vitamins.

The hospital went to court to force the family to continue chemotherapy.

Schimer was given the power to make medical decisions for Sarah after an appeals court ruling in October said the beliefs and convictions of the girl's parents can't outweigh the rights of the state to protect the child.

But Schimer has asked a Medina County court to let her drop her attempt to force Sarah to resume chemotherapy because it became impossible to make medical decisions for Sarah after the family fled their home near the village of Spencer, about 35 miles (56 kilometres) southwest of Cleveland.