Kallmann syndrome - how common is it ?

The only large scale study of Hypogonadotrophic hypogonadism (HH) and Kallmann syndrome cases came up with figures of:

1 in 4,000 births for HH
1 in 10,000 births for Kallmann syndrome

Experts estimate that both HH and Kallmann syndrome are under reported and under diagnosed.

Category:

Science & Technology

Tags:

• Kallmann syndrome
• Kallmann's syndrome
• delayed puberty
• absent puberty

[somegirlonthefloor]

im not sure, but I think the information is wrong. Im a women with kallmanns and I hear it was like 1 in 10,000 for men and 1 in 70,000 women this came straight from the KS website. your video is great, just a bit of wrong information.

[plymouthlad38]

All the estimates of numbers are just guesswork as there has been no reliable large study on KS & HH numbers.

Even the differences between men and women is quoted between being between 5 and 7 times more common in males. Some people say 5, others say 7.

The latest paper to quote a number gave the number of KS cases as 1 in 4,000 male births.

I think all we can say with certainity is that is is a rare condition that is probably widley under diagnosed in some places.

[plymouthlad38]

In KS and some forms of HH the olfactory bulb is not fully formed which gives the absent sense of smell.

If the olfactory bulb fails to develop it can prevent the release of a specific horomone from the hypothalamus called GnRH.

[plymouthlad38]

If part of the olfactory bulb is not fully formed or is absent it can prevent the hypothalmus from being able to control sex hormone production and puberty control.

[plymouthlad38]

There is a connection, just a little difficult to explain quickly.

In short the part of the brain controlling smell (olfactory bulb) and the part in overall control of sex hormone production (hypothalamus) lie very close together.

[XXYSexChromosomes]

Not criticising OK, just that XXY and Klinefelter syndrome are no longer synonymous, not that they ever were, people just like to make them synonymous. And as you quite rightly point out the difference between Kallmann and HH so too are XXY and Klinefelter syndrome different, after all these are the known karyotypes that can lead to Klinefelter syndrome:  XXY, XX (male) XXXY XXXXY XXYY XY/XXY :)

[GMPNY]

I wonder what the connection with lack of smell is? Such an unusual symptom. I agree it all has to be under reported and under diagnosed. Thanks for sharing the information :-)