Officials of the George Washington University School of Medicine said in an affidavit filed in D.C. Superior Court yesterday that Lillie Walker had been dismissed from the school's student body because of "repeated academic failures and consistent deficiencies in her behavior," rather than because of her race or personal appearance.

In an affidavit filed yesterday, Dr. L. Thompson Bowles, the school's dean of academic affairs said that Walker's academic record, her behavior and her "responses to medical school enviroment . . . prevent her functioning as a competent medical student."

In a suit filed May 13, Walker, 35, of 1121 24th St. NW, contended that the only course she had failed was an 18-day clerkship at the Psychiatric Institute in Rockville, and that the school's decision to dismiss her two weeks before graduation for academic reasions was "discriminatory, an abuse of discretion and made in bad faith."

Bowles's affidavit was George Washington's first detailed response to the complaint. It said that Walker, who is black, "has failed a major course in each of her three years of attendance at the Medical School, courses totaling 23 semester hours. Moreover, in several courses which she passes, she demonstrated minimal skills and abilities."

On the questions of personal appearance, Bowles noted in his affidavit that Walker had complained that she was "illegally evaluated" in this regard.

"To the contrary," Bowles said, "the evaluation (s) of Ms. Walker in her courses . . . have noted that she has appeared in clinical situations unkempt, unclean and in inappropriate attire . . . She has been observed in clinical settings in dirty lab coatsM a condition fundamentally inconsistent with the safety, healthy and welfare of patients."

Bowles said the medical school's academic regulations require the dismissal of any student who fails more than 20 hours of course work. He said Walker had chosen the clerkship at the Psychiatric Institute as one of her senior-year "electives."

The affidavit came to light following a meeting between Walker's attorneys and attorneys for the university in the chambers of Judge George Herbert Goodrich at Superior Court.

The university agreed to suspend the dismissal pending the outcome of a trial of Walker's suit, in which she seeks reinstatement and graduation. Both sides agreed to seek a trial date in July - early enough so that Walker's career plans would not be damaged if she wins.