Did small hominids have a genetic defect?

Miniature humans whose prehistoric remains were recently unearthed on an Indonesian island may have had a genetic disease known as Laron syndrome.

The 2004 discovery of Homo floresiensis (SN: 10/30/04, p. 275) suggested that this apparently close relative of Homo sapiens may have coexisted with modern humans as recently as 12,000 years ago (see page 37). The most-complete skeleton belonged to a woman who stood about a meter tall.

But the newfound specimens don't represent a distinct species at all, contends Zvi Laron of Tel Aviv University in Israel.

Various genetic mutations can produce Laron syndrome, in which the body is unresponsive to growth hormone. Laron discovered the disorder in 1966.

Now, he and his team have compared X rays of patients with Laron syndrome--who in Israel range from 108 to 136 centimeters in height--with data on H.floresiensis. They found numerous parallels: a pronounced ridge above the eyes, absence of a particular sinus in the head, and limbs that are abnormally short in proportion to the trunk.

Laron says that he would need to test DNA samples from the miniature hominids to prove his hypothesis. But it's difficult to extract DNA from such old bones.

"It's a nice theory," comments Ashley Grossman of Queen Mary, University of London. "It's going to be hard to substantiate."--B.H.