DNA studies carried out in Sardinia, the sun-drenched Italian island whose inhabitants are often on the short side, have helped identify only the second human 'height gene' known to science.
The gene, GDF5, appears to have two versions: one, connected to arthritis, which adds height; and another, connected to cartilage disease, which takes it away.
The presence of GDF5 in its various types and combinations can produce differences of up to 1.4 cm, according to the research.
Researchers stress that height in humans is only partly hereditary and in any case connected to many genes. The first of those genes, HMGA2, was revealed last September in the scientific journal Nature.
The studies which identified GDF5 as another factor involved 4,500 Sardinians whose DNA was studied as part of a project financed by the US's National Institute on Aging (NIA).
The SardiNIA project, in which US and Italian researchers worked together, is in turn part of a huge NIA programme of international research into aging.
Statistics show that the residents of Sardinia, the second largest island in the Mediterranean, tend to live longer than people in almost any other part of the world.
This fact, coupled with the 'pure' gene pool deriving from centuries of isolation, has meant that in recent years it has attracted genetic scientists in droves.
