What could be more 2025 than writing about internet speculation over a scientific study of Hitler’s DNA that hasn’t been published but is featured in a TV show that I haven’t watched? Well, there’s this: the US National Institutes of Health’s National Centre for Biotechnological Information says, “Kallmann syndrome is a congenital form of hypogonadism caused by low levels of hypogonadotropic hormones.” There are no such things as ‘hypogonadotrophic hormones’, only ‘gonadotrophic hormones’. I digress.
What is Kallmann syndrome?
Kallmann syndrome is one of the causes of hypogonadotrophic (meaning ‘low levels of gonadotrophic hormones’) hypogonadism (meaning ‘low levels of gonad function’), in which low levels of gonadotrophic hormones (GnRH, LSH, FSH) fail to stimulate the gonads (the ovaries in females or the testes in males). In Kallmann syndrome, hypogonadotropic hypogonadism is caused by a genetic developmental problem in which nerve cells that make GnRH do not develop properly. The olfactory (meaning ‘related to the sense of smell’) nerves are also affected, so people with Kallmann syndrome have low gonad function and their sense of smell is impaired. Partial or complete anosmia (meaning ‘no sense of smell’) from birth, and delayed or incomplete puberty, are the characteristic symptoms of Kallmann syndrome.
There are many different genetic causes of Kallmann syndrome. One of the genes involved is called PROK2 (prokineticin 2). Mutations in PROK2 in mice cause the same developmental defects that are seen in humans with Kallmann syndrome. Apparently, Hitler had a PROK2 mutation. This seems to be the basis for the claim that Hitler had Kallmann syndrome but it’s not enough to know for sure. Not everyone with PROK2 mutation has Kallman syndrome. If both copies of Hitler’s PROK2 gene were mutated, he’d likely have Kallmann syndrome, but if only one copy was mutated he might not.
Did Hitler have a micropenis?
It’s the possibility of Kallmann syndrome that leads to the speculation about Hitler’s penis. One of the scientists who helped analyse Hitler’s DNA is quoted as saying that “5% of cases get associated with a micropenis”. In fact, it seems that half of the males with Kallmann syndrome associated with abnormalities in PROK2 have a micropenis. So if Hitler had Kallmann syndrome, it’s a 50:50 chance that his penis would be abnormally small.
Cryptorchidism (undescended testes) seems to occur in a quarter of males with Kallmann syndrome associated with abnormalities in PROK2, so that’s less likely to have affected Hitler (despite what this song says).
You can’t have your cake and eat it too
There’s a fundamental problem with the idea that Hitler had Kallmann syndrome, from what I understand of the study.
The researchers didn’t compare the blood sample they used with a sample from any of Hitler’s living relatives. They apparently found a “perfect Y-chromosome match” with a sample collected 10 years ago, apparently from someone claiming to be Hitler’s son. (we get our Y-chromosomes from our dads, so they’re virtually the same between father and son).
The trouble is, Kallmann syndrome causes infertility. If Hitler had Kallmann syndrome, he couldn’t have had a son. Put another way, if the blood sample analysed for the TV show is Hitler’s, and it perfectly matches that of a son, he couldn’t have been infertile, so he very likely didn’t have Kallman syndrome. (Nowadays, gonadotrophin treatment can restore fertility in people with Kallmann syndrome but it wasn’t available in Hitler’s lifetime).
With Kallmann syndrome off the table, the chance of Hitler having a micropenis is the same as for any other male. Same goes for cryptorchidism.
Apparently, the researchers have submitted their study for publication in a scientific journal, which will subject their interpretations of their results to expert scrutiny. It will be interesting to see which of the sensational claims resulting from the TV show can be supported.
As the saying goes, ‘don’t let the truth get in the way of a good story’. Perhaps that’s why the show aired before publication of the research.
Image credit: Bundesarchiv Bild 183-S33882, Adolf Hitler retouched.jpg
