XPost: alt.fan.heinlein   
   From: wthyde1953@gmail.com   
      
   Dimensional Traveler wrote:   
   > On 2/14/2026 4:13 PM, William Hyde wrote:   
   >> Paul S Person wrote:   
   >>> On Thu, 12 Feb 2026 15:09:16 -0500, Cryptoengineer   
   >>   
   >>>> While I have a lot of issues with the Catholic church, its   
   >>>> extreme takes on how close a relative could marry (7 degrees of   
   >>>> separation) had the good effect of avoiding this inbreeding,   
   >>>> and also flattening society by destroying the 'hereditary clan'   
   >>>> or 'tribal' layer of social organization, and encouraging far   
   >>>> flung social connections.   
   >>>   
   >>> Except, of course, for the nobility and the royalty. Hemophilia   
   >>   
   >> Somewhere in her family tree, one of Victoria's ancestors, or Victoria   
   >> herself, had a mutation on her X chromosome which led to the most   
   >> famous cases of royal Hemophilia.  It was probably Victoria herself or   
   >> her mother, but it is just possible that it existed earlier and was   
   >> never passed to a male child.  Unlikely but possible.   
   >>   
   >> Queen Victoria had no siblings, but she passed her defective X   
   >> chromosome to three of her children.  As the elder sons were healthy   
   >> it did not become clear for some time that she carried the disease.   
   >>   
   >> Naturally the royalty of Europe were eager to marry into the royal   
   >> family of what was then the world's dominant power.  Some did this   
   >> before the disease was suspected, others took a chance, sometimes on   
   >> dubious medical advice (carriers generally bruise more easily than   
   >> non- carriers, and some experts were overconfident of their ability to   
   >> use this to detect a carrier).   
   >>   
   >> Poor Leopold, Alexei and the others were not victims of their   
   >> ancestor's martial practices. Just of bad luck and sometimes, bad   
   >> judgment.   
   >>   
   > My father was a hemophiliac from this matriarchal carrier type.  (It was   
   > a factor in his death in his 60's.)  Female children do not have   
   > hemophilia from this but pass it down.  Male children do not pass it   
   > down but have hemophilia.   
      
   Male sufferers cannot pass hemophilia onto their sons, as the son's x   
   chromosome must come from the mother.  On the other hand their daughters   
   are always carriers (unless they suffer from Turner Syndrome, I suppose).   
      
   If the mother is a carrier, and the father has the condition, the   
   daughter may also have the condition, and will certainly be a carrier.   
      
   In the past, of course, male children very rarely lived long enough to   
   be fathers, except in the case of mild hemophilia.  When the damage to   
   the genes is severe, female carriers can show symptoms, though they   
   always have enough clotting factor to avoid hemophilia.   
      
   It seems that that female carriers who show symptoms may also do so   
   owing to Lyonnisation, in which one of a females two copies of a gene on   
   the x chromosome is inactivated - more or less.   
      
   It is theoretically possible, IIRC (which I may not) for this process to   
   lead to a female hemophiliac, but this is considered very unlikely and   
   has never been observed.   
      
   If the woman in question is a carrier, and one of her healthy clotting   
   factor genes is suppressed, her clotting factor will be low, but not in   
   the hemophiliac range.   
      
      
   William Hyde   
      
      
   William Hyde   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)