Understanding the genetic basis of human appearance is a fascinating scientific area but surprisingly little is known thus far. In a forensic context, retrieving information on externally visible characteristics of a sample donor solely from the crime scene sample can provide valuable information for finding unknown individuals who usually cannot be identified via conventional DNA profiling. However, it is expected that many - if not all - externally visible characteristics are quantitative traits where different genes and also environmental factors can contribute to the phenotype. This troubles not only the search for underlying genes but also attempts to predict the traits. We are therefore concentrating on unveiling the genetic basis of human appearance using, amongst other techniques, the genome-wide association approach. Furthermore, we are determining the most-predictive bio-markers, and developing molecular tools for predicting externally visible characteristics for practical applications such as in forensics.

Selected recent publications:

• Kayser M, Liu F, Janssens ACJW, Rivadeneira F, Lao O, van Duijn K, Vermeulen M, Arp P, Jhamai MM, van IJcken WFJ, den Dunnen JT, Heath S, Zelenika D, Despriet DDG, Klaver CCW, Vingerling JR, de Jong PTVM, Hofman A, Aulchenko YS, Uitterlinden AG, Oostra BA, van Duijn CM (2008) Three genome wide association studies and a linkage analysis identify HERC2 as a human iris color gene. American Journal of Human Genetics, 82(2):411-423.
• Kayser M and Schneider PM (2009) DNA-based prediction of human externally visible characteristics in forensics: motivations, scientific challenges, and ethical considerations. Forensic Science International: Genetics, 3:154–161.
• Liu F, van Duijn K, Vingerling JR, Hofman A, Uitterlinden AG, Janssens ACJW, and Kayser M (2009) Eye color and the prediction of complex phenotypes from genotypes. Current Biology, 19 (5):R192-R193
• Estrada K, Krawczak M, Schreiber S, van Duijn K, Stolk L, van Meurs JBJ, Liu F, Penninx BWJH, Smit JH, Vogelzangs N, Hottenga JJ, Willemsen G,  de Geus EJC, Lorentzon M, von Eller-Eberstein H, Lips P, Schoor N, Pop V, de Keijzer J, Hofman A, Aulchenko YS, Oostra BA, Ohlsson C, Boomsma DI, Uitterlinden AG, van Duijn CM, Rivadeneira F, Kayser M (2009) A genome-wide association study of northwestern Europeans involves the CNP signaling pathway in the etiology of human height variation. Human Molecular Genetics, 18 (18):3516-3524.
• Liu F, Wollstein A, Hysi PG, Ankra-Badu GA, Spector TD, Park D, Zhu G, Larsson M, Duffy DL, Montgomery GW, Mackey DA, Walsh S,  Lao O, Hofman A, Rivadeneira F, Vingerling JR, Uitterlinden AG, Martin NG, Hammond CJ, and Kayser M (2010) Digital quantification of human eye color highlights genetic association of three new loci. PLoS Genetics, 6 (5):e1000934,
• Walsh S, Liu F, Ballantyne K, van Oven M, Lao O, Kayser M (2010) IrisPlex: a sensitive DNA tool for accurate prediction of blue and brown eye colour in the absence of ancestry information. Forensic Science International: Genetics, Epub 29 March 2010, doi:10.1016/j.fsigen.2010.02.004
• Walsh S, Lindenbergh A, Zuniga SB, Sijen T, de Knijff P, Kayser M, and Ballantyne KN (2010) Developmental validation of the IrisPlex System: Determination of blue and brown iris colour for forensic intelligence. Forensic Science International: Genetics, Epup 14 October 2010, doi:10.1016/j.fsigen.2010.09.008
• Zubakov D, Liu F, van Zelm MC, Vermeulen J, Oostra BA, van Duijn CM, Driessen GJ, van Dongen JJM, Kayser M, Langerak AW (2010) Estimating human age from T cell DNA rearrangements. Current Biology, 20(22):R970
• Branicki W, Liu F, van Duijn K, Draus-Barini J, Pośpiech E, Walsh S, Kupiec T, Wojas-Pelc A, and Kayser M (2011) Model-based prediction of human hair color using DNA variants. Human Genetics, Epub Jan 4 2011, DOI 10.1007/s00439-010-0939-8