Thursday, April 21, 2011

The reputation of the Duchess of Kent

Until recently the incidence of haemophilia among descendants of Queen Victoria raised a most delicate medico-historical question. Queen Victoria was a carrier of the disease, but from which of her parents did she inherit it? Her father, the Duke of Kent, was the fourth son of King George III and Queen Charlotte. The duke was not a haemophiliac. So Victoria’s mother, a German princess of Saxe-Coburg-Saalfeld, must have been a carrier. Yet there is no sign of any incidence of haemophilia among any of the Duchess of Kent’s proximate or even distant relations. Neither her father nor her grandfather were sufferers, and nor were any of her siblings, nor any of their non-British descendants, including the entire Belgian royal family, nor any known members of the duchess’s mother’s family of Reuss-Ebersdorf, nor indeed any known descendant of theirs. The duchess had another child by a previous marriage, and none of the descendants of Queen Victoria’s half-sister Princess Feodora of Hohenlohe-Langenburg ever developed the disease.

Naturally the task of historical diagnosis is much harder at this distance, because certain early nineteenth-century infant deaths could have been the result of severe haemophiliac haemorrhaging. But one would expect to see the kind of cluster of obvious cases that occurred among the families of Queen Victoria’s daughters Princess Alice and Princess Beatrice, and of her youngest son Prince Leopold, who was himself a sufferer. This was never the case in any branch of the Saxe-Coburg-Saalfeld or Reuss-Ebersdorf or Hohenlohe-Langenburg families. Up to the end of the nineteenth century it was the custom for at least one British cabinet minister to witness royal births and certify that any additions to the line of succession to the throne were legitimate. This was certainly the case when Princess Victoria was born at Kensington Palace at 4.15 a.m. on May 24, 1819, so we can safely assume that the Duchess of Kent really was the future queen’s mother. But she was almost certainly not a carrier of haemophilia. Therefore for a long time the only medical conclusions to be reached appeared to be either that (a) Queen Victoria’s haemophiliac gene was the result of a “de novo” or spontaneous mutation, of which the chance was thought to be very slight—or (b) Queen Victoria’s biological father was someone other than the Duke of Kent, presumably a man with so mild a case of haemophilia that he survived into adulthood and may never have been diagnosed at all.

It all depends on whether Queen Victoria carried haemophilia A or B. Hitherto it was presumed that Queen Victoria carried haemophilia A, and it is apparently true, or was once thought to be true, that spontaneous mutations are far rarer in that event than in cases of haemophilia B. But new information is to hand. The task of positively identifying the mortal remains of members of the family of Tsar Nicholas II was lately accomplished in Russia, partly thanks to the willingness of the present Duke of Edinburgh to donate genetic material—the Duke’s mother’s mother’s mother (Queen Victoria’s daughter Princess Alice) was also the mother of the Tsarina, and so his mitochondrial DNA provided a reliable benchmark. An unexpected consequence of this grisly task, however, was to gain an opportunity to study genetic material from the remains of the Tsar’s haemophiliac son and heir, and the results of that analysis were lately published in
Science by a team led by Evgeny I. Rogaev. Inter alia, they conclude that the form of haemophilia that descended from Queen Victoria was haemophilia B, not A, and “was likely caused by a point mutation in F9, a gene on the X chromosome that encodes blood coagulation factor IX,” that is to say Queen Victoria’s own X chromosome. This may well have been the one and only spontaneous thing that ever happened to Queen Victoria, and it is a happy consequence of these findings that any lingering doubt about this aspect of the honour of Her Majesty’s mother, the Duchess of Kent, may now safely be dispelled.

No comments:

Post a Comment