Kallmann Syndrome is a rare enough condition without having trouble finding information on the internet because of spelling...

The German / American scientist who published the landmark paper on this syndrome in 1944 was Franz Kallmann.

The correct notation is now Kallmann Syndrome, rather than Kallmann's Syndrome. It was recently agreed that all the personal notation associated with disease names would be dropped, so for instance Down's syndrome is now Down syndrome and Klinefelter's is now Klinefelter syndrome.