Study points to new genetic model for disease

LONDON — A novel mode of inheritance has been discovered that may prompt scientists to re-evaluate the genetic basis of disease. In 21 September Science, Nico Katsanis and colleagues, from the Baylor College of Medicine (BCM), Houston; Institute of Child Health, London and the Simon Fraser University, British Columbia have shown that the well-defined boundaries between classical Mendelian traits and complex traits may, in fact, be blurred.

Katsanis et al. found that mutations in three alleles from two genes combine to result in a rare genetic disorder called Bardet–Biedel syndrome (BBS) — previously thought to have been caused by a single gene effect.

"We have known that genes interact for a long time, but we have only looked at both ends of the scale, that is, from a one gene-one disease model to a complex mode of inheritance which involves several genes plus environmental factors," said Katsanis.

"But we have ...