Kallmann syndrome (KS) is a form of a condition known as hypogonadotropic hypogonadism (HH). HH is a condition that causes a disruption to the normal production of hormones that control puberty and fertility.
Kallmann syndrome is a specific form of HH where the sense of smell is affected as well. People with KS will have no sense of smell or a very limited sense of smell from birth.
Apart from the sense of smell, KS is the same condition as HH.
HH is normally present from birth, where puberty is affected, or it can occur after a normal puberty when it affects fertility.
If present from birth puberty will not start correctly or fully complete. Some pubertal development will occur but not progress as normal.
The majority of people with KS / HH will be infertile.
KS / HH occurs in both males and females but is more commonly diagnosed in males.
KS / HH can occur with one or more, or none of these additional physical symptoms:
· Hearing problems
· Mirror movements of the hands
· Cleft lip / palate
· Missing teeth
· Fused fingers or toes
· Scoliosis
· Missing kidney
· Undescended testicles
Diagnosis is normally achieved by excluding other conditions that can affect puberty and fertility. There is no one single blood or genetic test that can firmly diagnose KS / HH.
Patients are sometimes labelled as "late bloomers" or "late developers" and can wait many years before receiving the correct diagnosis.
Hormone replacement therapy can produce most of the changes normally seen at puberty but will not induce fertility. Hormone replacement therapy, to replace the testosterone or oestrogen / progesterone hormones that are not being produced, is normally required lifelong.
Specialised treatments are available to help achieve fertility for both male and female patients but can be expensive and not always easy to acquire.
The genetics of KS / HH is complex and far from being totally understood. Genetic testing can help in some cases but does not always provide clear cut answers on the chances of passing on the condition.
