Source: Netherlands Organisation for Scientific Research

Geneticists of Leiden University Medical Centre (LUMC) in the Netherlands are the first to determine the DNA sequence of a woman.

The woman is LUMC clinical geneticist Dr Marjolein Kriek, who follows in the footsteps of the first sequence, which was a combination of persons, in 2001. The sequences of Jim Watson, discoverer of the DNA's double helix structure, followed in 2007, and that of gene hunter Craig Venter. Recently the completion of the sequences of two Africans was announced.

"If anyone could properly consider the ramifications of knowing his or her sequence, it is a clinical geneticist," Professor Gert-Jan B van Ommen, leader of the LUMC team said.

"Moreover, while women don't have a Y-chromosome, they have two X-chromosomes. As the X-chromosome is present as a single copy in half the population, the males, it has undergone a harsher selection in human evolution. This has made it less variable.

"We considered that sequencing only males, for 'completeness', slows insight into X-chromosome variability. So it was time, after sequencing four males, to balance the genders a bit. And after Watson we also felt that it was okay to do Kriek."

The sequence will be made public, except incidental privacy-sensitive findings and the results will hopefully contribute to insights into human genetic diversity.