The investigations carried on the DNA of the royal mummies published in february 2010 have provided material for a new genealogical tree for the royal family of the late XVIIInth dynasty. After discussing the reliability of this study, a close examination of these results leads to the conclusion that some genetical links excaped to the team of geneticians. The most significant being the fact that Yuya shares with his son-in-law Amenhotep III about 1/3 of genetical inheritance. It is consequently proposed that Yuya was an uncle of Amenhotep III, Mutemwiya being his sister. This means that queen Tiyi was in fact an actual cousin of Amenhotep III. Extrapolating to the next generation it is also suggested that Amenhotep IV Akhenaten equally married his own cousin, Nefertiti, whose parents were related to both Amenhotep III and Yuya. This would explain why the DNA of Amenhotep IV Akhenaten (mummy KV 55) and that of Nefertiti, identified to mummy KV 35 YL, were looking like that of siblings. It is also suggested that Tutankhamun was the seventh child of Amenhotep IV Akhenaten and Nefertiti in accordance with some reappraised epigraphic evidences, and that Mutemwiya is no other than the mummy KV21A. A new genealogical tree based on DNA and epigraphic data is given in conclusion.