Kallmann syndrome is a form of hypogonadotrophic hypogonadism (HH).
Kallmann syndrome can be described as HH with an associated lack of sense of smell.
As far as diagnosis & treatment is concerned there is no difference between Kallmann syndrome and HH.
Hypogonadism is the condition where the gonads (testes in men, ovaries in women) stop functioning correctly and do not produce the hormones they normally do. This is a fairly common occurrence in older age, especially in men when testosterone levels can fall from middle age onwards.
Hypogonadotrophic hypogonadism (HH) is not the same condition and is a lot rarer than normal hypogonadism. Normally the testes & ovaries are controlled by hormones produced by a structure within the brain called the pituitary gland. These hormones are called gonadotrophins.
In HH the levels of gonadotrophins are so low as to prevent the testes & ovaries from functioning correctly.
In normal hypogonadism the testes & ovaries did function correctly at one stage.
In HH the testes & ovaries never had the chance to function correctly as they never had the correct gonadotrophin levels produced by the pituitary in order to perform correctly.
Gonadotrophins = hormones that act on the gonads (ovaries / testes)
Hypogonadism = under performance by the testes / ovaries
Hypogonadotrophic hypogonadism = under performance by the testes / ovaries due to low levels of gonadotrophins.
In Kallmann syndrome / HH the failure to enter puberty is due to the lack of gonadotrophin release by the pituitary gland which prevents the development of the testes / ovaries normally seen at puberty.
Sunday, October 24, 2010
Saturday, October 23, 2010
Questions to ask the GP if you are worried about delayed puberty:
Puberty in boys should start between the ages of 12 – 14 and in girls between the ages of 11 – 13.
Some boys will always be later than other boys and there is a fundamental difference between a “constitutional delay of puberty” and a case of Kallmann syndrome.
Kallmann syndrome is a very rare condition and will not be the first condition that a GP would normally suspect when presented with a case of absent puberty.
It has been common for GP’s to have a “wait and see” approach to cases of delayed puberty, assuming that puberty will start eventually. For a lot of boys this indeed would be the case. However in a case of Kallmann syndrome puberty will not commence without treatment. It is not uncommon for people with Kallmann syndrome to be dismissed by their doctors so often as late developers they loose faith in going forward with such an embarrassing condition. It is not that uncommon for men to get into their 20’s or 30’s before a correct diagnosis is reached.
Experts in Kallmann syndrome now suggest that any boy who has not started puberty by 15 or a woman not started having periods by 14 should be referred to an endocrinologist for specialist review. An endocrinologist can then differentiate between a case of delayed puberty and a potential case of Kallmann syndrome.
If a boy has not started puberty by 14 or a girl who has not started periods by 13 and the levels of the pituitary hormones LH and FSH are low there should be no reason for a delay for a referral to an endocrinologist. The presence of other signs such as lack of sense of smell, family history of “late developing” or infertility, un-descended testes at birth should make an early referral even more important. This is particularly important with women as there can be a wide range of conditions that could prevent periods from commencing and it is important to get the correct diagnosis quickly.
What is the best age for treatment to start:
The age treatment starts will depend on a number of factors which the endocrinologist has to take into account. In younger patients there is a balance to be made between the time treatment starts and the dosage used. Before the age of 16 some doctors are reluctant to give the full adult dose of testosterone (around 200 – 400 mg per month) until it is sure that normal adult height is obtained. If full dose treatment starts too early it can risk fusing the growth plates of the long bones too early and full height is not obtained.
Once full adult dose treatment starts changes should normally start occurring within 6 months. One important point to bear in mind is that the levels of testosterone should be monitored during treatment so that the levels are of adequate adult dose throughout the treatment cycle.
For the younger patients, for ages from 13 – 16, doctors often use a step by step approach starting in small doses of testosterone, such as 50 or 100 mg per month. This is normally reviewed at 3 month or 6 month stages to see if there are any signs of pubertal development. If there is any increase in testicular size it could suggest that it is a case of delay of puberty rather than Kallmann syndrome. The doctor will then re-check the levels of the pituitary hormones LH and FSH to confirm the diagnosis. If LH & FSH remain low the doctor may step up the dose up to adult levels, the rate this occurs will vary from patient to patient but in general by the age of 16 the full adult dose is normally given. The treatment is normally in the form of injectable testosterone (Sustanon or Nebido) as this gives the best effectiveness. Oral testosterone is unlikely to be suitable to patients with Kallmann syndrome.
What changes will occur:
This will depend on the age treatment starts. A person with Kallmann syndrome will never go through a totally normal puberty while on hormone replacement therapy as the testes will not grow and the ovaries will not function. However all the other secondary sexual characteristics should occur including body & pubic hair growth, muscle development, voice breaking and a more adult like appearance.
Penile size is an issue for all men and not just those with Kallmann syndrome. As a general rule the earlier treatment starts, ideally before the age of 16, the more chance there is of a normal penile length. The later the treatment starts the less chance there is of the treatment of having any effect on penile size.
Changes should start occurring within six months of treatment and may take up to two years to complete as in any person going through puberty.
Puberty in boys should start between the ages of 12 – 14 and in girls between the ages of 11 – 13.
Some boys will always be later than other boys and there is a fundamental difference between a “constitutional delay of puberty” and a case of Kallmann syndrome.
Kallmann syndrome is a very rare condition and will not be the first condition that a GP would normally suspect when presented with a case of absent puberty.
It has been common for GP’s to have a “wait and see” approach to cases of delayed puberty, assuming that puberty will start eventually. For a lot of boys this indeed would be the case. However in a case of Kallmann syndrome puberty will not commence without treatment. It is not uncommon for people with Kallmann syndrome to be dismissed by their doctors so often as late developers they loose faith in going forward with such an embarrassing condition. It is not that uncommon for men to get into their 20’s or 30’s before a correct diagnosis is reached.
Experts in Kallmann syndrome now suggest that any boy who has not started puberty by 15 or a woman not started having periods by 14 should be referred to an endocrinologist for specialist review. An endocrinologist can then differentiate between a case of delayed puberty and a potential case of Kallmann syndrome.
If a boy has not started puberty by 14 or a girl who has not started periods by 13 and the levels of the pituitary hormones LH and FSH are low there should be no reason for a delay for a referral to an endocrinologist. The presence of other signs such as lack of sense of smell, family history of “late developing” or infertility, un-descended testes at birth should make an early referral even more important. This is particularly important with women as there can be a wide range of conditions that could prevent periods from commencing and it is important to get the correct diagnosis quickly.
What is the best age for treatment to start:
The age treatment starts will depend on a number of factors which the endocrinologist has to take into account. In younger patients there is a balance to be made between the time treatment starts and the dosage used. Before the age of 16 some doctors are reluctant to give the full adult dose of testosterone (around 200 – 400 mg per month) until it is sure that normal adult height is obtained. If full dose treatment starts too early it can risk fusing the growth plates of the long bones too early and full height is not obtained.
Once full adult dose treatment starts changes should normally start occurring within 6 months. One important point to bear in mind is that the levels of testosterone should be monitored during treatment so that the levels are of adequate adult dose throughout the treatment cycle.
For the younger patients, for ages from 13 – 16, doctors often use a step by step approach starting in small doses of testosterone, such as 50 or 100 mg per month. This is normally reviewed at 3 month or 6 month stages to see if there are any signs of pubertal development. If there is any increase in testicular size it could suggest that it is a case of delay of puberty rather than Kallmann syndrome. The doctor will then re-check the levels of the pituitary hormones LH and FSH to confirm the diagnosis. If LH & FSH remain low the doctor may step up the dose up to adult levels, the rate this occurs will vary from patient to patient but in general by the age of 16 the full adult dose is normally given. The treatment is normally in the form of injectable testosterone (Sustanon or Nebido) as this gives the best effectiveness. Oral testosterone is unlikely to be suitable to patients with Kallmann syndrome.
What changes will occur:
This will depend on the age treatment starts. A person with Kallmann syndrome will never go through a totally normal puberty while on hormone replacement therapy as the testes will not grow and the ovaries will not function. However all the other secondary sexual characteristics should occur including body & pubic hair growth, muscle development, voice breaking and a more adult like appearance.
Penile size is an issue for all men and not just those with Kallmann syndrome. As a general rule the earlier treatment starts, ideally before the age of 16, the more chance there is of a normal penile length. The later the treatment starts the less chance there is of the treatment of having any effect on penile size.
Changes should start occurring within six months of treatment and may take up to two years to complete as in any person going through puberty.
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