Although no two human beings, even identical twins, have the same fingerprints, there are some people who have none. Now Israeli researchers have deciphered the genetic basis of a rare disease responsible for the absence of prints on certain people's fingertips. The research, to be published in the October issue of the prestigious American Journal of Human Genetics, provides new information on the complex biological processes leading to the formation of fingerprints, which has been meager until now. Researchers led by Prof. Eli Sprecher of Rambam Medical Center and the Technion-Israel Institute of Technology's Rappoport Faculty of Medicine, have succeeded in understanding the genetic basis of Naegeli syndrome, which features congenital absence of fingerprints. Their work was made possible thanks to the initial efforts of two members of the group, Gabriele Richard and Peter Itin, who succeeded in assembling a very large group of patients. Although biological material was collected more than two decades ago, only recently could Jennie Lugassy, a graduate student in Sprecher's lab, show that the disease results from abnormal function of a wellknown protein named keratin 14. Sprecher explains why it took so long to identify the cause of the disease: "Keratin 14 had been known for years to be associated with a skin disease very different from Naegeli syndrome, which is why abnormal function of this protein was not considered for so many years as the cause of Naegeli syndrome." Keratin 14 is part of the cell cytoskeleton. In most diseases arising from defective function of this protein, cells become overly sensitive to mechanical stress, and as a result, skin blistering occurs. Now, it seems that the defect in keratin 14 causing Naegeli syndrome is unique in that it does not lead to skin fragility but rather induces programmed cell death in the upper skin layers, which may explain the unusual features of the disease such as absence from birth of fingerprints and impaired sweating ability. The researchers are now busy trying to understand the connection between the absence of fingerprints and enhanced programmed cell death.