Sisters Collect Their, Er, Lambskins : Education: They earn diplomas from Cal State L.A. at ages 14 and 19.

Cynthia Martel is learning to live with the sobriquet “Doogie Howser”--a reference to the 16-year-old physician who is the title character of a popular ABC television series. But, she thinks the comparison is not quite accurate.

“I’m not nearly as young as the guy on the show is supposed to be,” Cynthia says. “He went to college at 6.” Cynthia, you see, started college at 10.

Now 14, she will accept her diploma today from Cal State Los Angeles, where she becomes the youngest student ever to graduate from the Monterey Hills campus. An honors student in biology and biochemistry, she has been accepted by the medical schools at Yale, Johns Hopkins and USC.

Cynthia and her sister Belinda, who also graduates today at the advanced age of 19, are beginning to realize that their lives up to now might seem a tad unusual. Schooled mostly at home by their parents--their father is a laboratory technician, their mother a college chemistry instructor--both girls qualified for the college’s early entry program by scoring in the top 5% on the Scholastic Aptitude Test.

By then, Belinda had had a few years in the Big Bear public school system. Her precociousness allowed her to skip a couple of years, she says, and made her stand out among classmates.

“I got called a nerd and a bookworm,” says Belinda, a French major. “One guy socked me in the lip. I felt a whole lot more accepted (studying) with my mother, a whole lot more in my element. The only thing I missed about public school was the prom.”

What about such teen-age pursuits as mall-hopping and dating? Cynthia has male friends, but most of them are in their 20s. “I don’t interact too much with kids my own age,” says the 14-year-old, who has just completed her chemistry honors thesis on plasma and liver proteins. “I wouldn’t say that they’re immature. It’s just that they seem a lot more worried about having fun than doing their school work.”

“The main thing with them is boys, clothes and makeup,” Belinda says.

The older sister is the extrovert of the pair. “Cynthia is very mature for her age,” says Belinda, who has not settled on a plan for next year. “She’s probably the most mature member of the family. . . . I go off on tangents and do really weird things.”

Jan Slater, head of Cal State L.A.’s early entrance program, one of only three such programs in the nation, says putting a 10-year-old in college, or even a 15-year-old, as Belinda was as a freshman, can be risky. “They need support, some more than others. They can have problems with things . . . time organization problems.”

What about the Martel sisters? Slater didn’t hesitate. “It was perfect for them.”