'Hedgehog' Genes Determine Tall or Short

April 7, 2008 -- Want to know if your baby will be tall or short? Perhaps you should consult a hedgehog.

In a trawl through the human genome, scientists have netted a cluster of key genes that influence height, and some of the DNA nuggets are genes that control lyrically-named proteins called sonic hedgehog, Indian hedgehog and desert hedgehog.

The study by British scientists, published on Sunday in the journal Nature Genetics, entailed sifting through samples from more than 30,000 people of European descent to look for common variations in the genetic code that help determine height.

The sleuths found 20 new regions, or loci, of the genome that, put together, can make a difference in height of up to six centimeters (2.4 inches).

Unlike obesity, which is driven by genetic and environmental factors, height is almost entirely a genetic affair.

Ninety percent of normal variation in human height can be attributed to one's DNA heritage rather than nutrition.

The 20 loci account for roughly three percent of this 90 percent. Last September, the same team found a genetic variant that accounted for another 0.3 percent.

Some of the 20 genes spotted in the new probe are well known and their function has been intensively explored.