So Stanford did an osmotic fragility test - fancy way of saying sticking red blood cells in water to see if they burst as they do with hereditary spherocytosis and so they did this test with Fionn's blood. They told me they expected it to be positive as they saw some spherecyotes under microscope at first visit
Well results came back and its negative.
So - in a halfway land here - their take now is that he maybe doesnt have HS (Yeah!) but come back in 2 months and retest again but likely he doesnt have it.
Exciting news so fingers crossed. If its just so mild that not triggering the test that would be fantastic news.