The skeleton of a young man who lived in a prehistoric hunter-gatherer society and who was also a severely deformed dwarf has been discovered in an 11,150-year-old grave site in southern Italy.

Anthropologists say the skeleton is evidence that even under the rigorous way of life imposed by the practice of nomadic hunting and gathering, early societies were able to accept and care for the severely handicapped.

Fossil remains of early humans who suffered various disabling deformities have been known for some time, but all were the result of accidents or illness in later life. The Stone Age dwarf is the most ancient known human who was born with obvious major handicaps.

The dwarf, who stood between 3 feet 4 and 4 feet 4 when he died at age 17, probably had difficulty walking great distances and had limited use of his hands and arms. The arm bones, for example, show that it was impossible for him to extend his elbows fully.

Although the skull shows several abnormalities such as bulges over the eyes and ears, people with comparable forms of dwarfism today have normal intelligence.

Though the youth was probably not an economically productive member of his society, he was accorded special funeral treatment. His grave was one of the few in an Italian cave that is unusual because it has paintings on the walls. The cave probably served as a center of ritual life.

According to a report in last week's Nature, the youth had acromesomelic dysplasia, a form of dwarfism that is rare today. It is known to be caused by inheriting one recessive gene for the condition from each parent. Because the parents carried the gene, though presumably both were normal themselves, the existence of the youth suggests some degree of inbreeding among Paleolithic populations.

The skeleton was discovered in Riparo del Romito in Calabria, the toe of the Italian boot. The report in Nature was authored by David W. Frayer of the University of Kansas, William A. Horton of the University of Texas at Houston, Roberto Macchiarelli of the Museum of Prehistory and Ethnography in Rome and Margherita Mussi of the University of Rome.