Two Harvard scientists reported in today's issue of the New England Journal of Medicine that they successfully identified a single gene in a human fetus cell.

Dr. Stuart Orkin, a research fellow in Pediatrics, and Dr. David Nathan '51, Robert A. Stranahan Professor of, Pediatrics, along with other scientists from Yale University and Haceteppe University in Turkey, made the discovery, which enables doctors to detect certain genetic diseases in unborn babies.

"Identifying single genes is not a new phenomenon," Orkin said yesterday, "The breakthrough is in identifying a gene from a fetus."

"It is now theoretically possible to detect such illnesses as sickle-cell anemia and cystic fibrosis," Orkin said. "All you have to find out is what to look for in the gene."

Orkin explained that the image produced was a row of fuzzy-looking black bands. If one of the bands is missing, the gene is defective, he added.

Before the discoverty was made, the only way to tell if a fetus was anemic was to take a blood sample. Orkin called this "a risky procedure." The new technique allows doctors to look at hemoglobin cells from the fluid around the fetus.

Presently the method of identification can detect two types of anemia, alphathalassemia and beta-delta-thalassemia. The most common type of anemia in the country, beta-thalassemia (Cooley's anemia) cannot be detected yet.

Dr. Arthur W. Nienhus of the National Heart, Lung and Blood Institute wrote an editorial in the journal claiming: "This is the first direct examination of the gene. The power of the technique is extraordinary, but the actual execution of it, once mastered, is not terribly difficult."

The isolation of the gene was the second landmark in genetics this week. On Tuesday, the first known baby conceived in a laboratory was born by Ceasarean section in Lancashire, England.