Kallmann Syndrome (KS) and Congenital Hypogonadotropic Hypogonadism (CHH)
Kallmann Syndrome (KS) and Congenital Hypogonadotropic Hypogonadism (CHH)
Kallmann Syndrome (KS) and Congenital Hypogonadotropic Hypogonadism (CHH) are rare genetic conditions that affect sexual development and reproductive health. Both conditions are caused by a deficiency or dysfunction of gonadotropin-releasing hormone (GnRH), which is responsible for stimulating the production of sex hormones. The primary difference between the two is the sense of smell:
Kallmann Syndrome (KS) includes a reduced or absent sense of smell (anosmia or hyposmia).
CHH involves normal olfactory function.
Despite this difference, both conditions result in delayed or absent puberty and infertility without medical intervention.
Lack of testicular development or micropenis in males (not always present)
Infertility
Delayed bone growth
Low libido or energy
Reduced or absent sense of smell (in KS)
Other features may be present depending on the underlying genetic variant, such as:
Cleft lip or palate
Hearing loss
Color blindness
Missing teeth (dental agenesis)
Shortened fourth fingers or toes
More than 50 genes have been associated with KS/CHH, and genetic testing is now available to help confirm diagnosis, especially when a family history exists.
Diagnosis and Testing
Diagnosing KS/CHH typically involves:
Blood tests to assess hormone levels (FSH, LH, testosterone/estrogen)
MRI scans to examine the hypothalamus and olfactory bulbs
Genetic testing via blood or saliva samples
Olfactory testing (to detect anosmia or hyposmia)
These diagnostic tools can now be used as early as infancy, especially in families with known genetic variants.
Fertility and Hormone Treatment
Although KS/CHH affects fertility, modern treatment options are highly effective. These include:
Hormone Replacement Therapy (HRT) to induce puberty and maintain general health
Assisted Reproductive Techniques, such as:
Hormonal injections
In Vitro Fertilisation (IVF) in advanced cases
Patients undergoing fertility treatment are carefully monitored through scans and hormone levels. Clinics often limit the number of mature follicles to reduce the risk of multiple births.
Support and Resources
You don’t have to face this journey alone. The support group offers invaluable resources, education, and a supportive community for those living with KS/CHH.
This is a private group. Makes people feel comfortable sharing sensitive info. They can feel secure knowing the info they share isn’t seen by any other Facebook groups or friends on Facebook within here
Did You Know?
KS is named after Franz Joseph Kallmann, who first described the condition in 1944.
Notable individuals with KS include the jazz vocalist Jimmy Scott, who brought visibility to the syndrome through his music and public story.
Living with KS/CHH
With proper diagnosis and medical support, individuals with KS/CHH can lead healthy, fulfilling lives. Hormonal therapy enables puberty to progress, supports bone and cardiovascular health, and allows for the possibility of fertility in both men and women.
The journey with a rare condition can be isolating, but you are not alone. Many have walked this path, found answers, and now advocate for others.
Here’s a personal insight from a member of the Kallmann Syndrome (KS) community:
A Personal Journey with Kallmann Syndrome (Shared Anonymously)
As a child in primary school, especially in P6 and P7, I appeared to be developing normally—body hair and other signs of puberty were present. Strangely, I noticed many of my peers weren’t developing in the same way. I felt embarrassed and awkward about my body, so much so that I would shave just to blend in. It seemed easier to hide what made me different.
As I entered my early teens, I still hadn’t started my period. I had also struggled with anorexia and was admitted to Craigavon Area Hospital, where doctors began to investigate whether my eating disorder was delaying puberty. After various tests, I was told everything looked normal and that I might just be a “late developer.”
But by age 15 or 16, with still no sign of menstruation, I was referred to the Royal Victoria Hospital in Belfast, where I came under the care of Professor Akinston. After a short hospital stay and several tests, I casually mentioned that I had no sense of smell. That one piece of information led to a diagnosis: Kallmann Syndrome.
I had never heard of it before. I felt utterly alone. At the time, there were no support groups, no one to talk to, and very little information available. I remember learning that it mainly affected males, and that women with the condition were even rarer—roughly 1 in 120,000 women, compared to 1 in 50,000 men. That made me feel like a freak, isolated in a condition that nobody around me understood.
I only knew of one other person: a man named Mark Saunders, who had created a help booklet and a former support group. His work was one of the few lifelines available back then.
Years later, after storing my DNA profile with the genetics team at City Hospital in Belfast, I was told they had identified a gene mutation—PROKR2, position 254, changing from G to A. This specific mutation is rare, affecting only about 5% of KS patients. Finally, I had genetic confirmation, something that had eluded me for years and made me question whether my diagnosis was even real.
With time, curiosity turned into purpose. I founded a Facebook support group, which now connects over 2,000 members from around the world. I started it because I didn’t want anyone else to feel the loneliness and confusion I felt growing up. Knowing there are others who understand makes all the difference.
Even so, accepting my diagnosis hasn’t been easy. In my teenage years, I was prescribed the contraceptive pill to induce a monthly bleed—a constant reminder of my condition. I eventually stopped taking the medication, trying to forget what it represented. That choice had consequences: I developed osteopenia and osteoporosis, conditions that could have been prevented with proper hormone replacement therapy.
If you’re reading this and have KS or CHH, please—take your medication. It’s not just about fertility or puberty; it’s about your bones, your heart, and your future health.
Despite everything, I’m now a mother to four children—one of whom is my angel, forever 18—and three others, including twins. Motherhood has been both healing and motivating. I still struggle to fully accept KS, but I channel my energy into researching and preparing—not for myself, but in case my children are ever affected.
I’m especially grateful to the incredible Dr. Neil McClure at the Regional Fertility Clinic in Belfast. His compassion, expertise, and support were life-changing for me.
Kallmann Syndrome can be sporadic or inherited, and while my specific mutation may carry a lower risk of being passed on, I continue to search for answers for my children’s future.
Support and awareness are everything. In recent years, I’ve learned that mental health issues like anxiety and depression are more common in people with KS than previously thought. I’ve faced social anxiety and depression myself. The tragic loss of a young man from our online support community opened doctors’ eyes to the emotional toll this condition can take. Thankfully, more professionals are now recognising and addressing these hidden aspects of our condition.
To anyone out there feeling lost or alone: you are not a freak, and you are not alone. There is support. There is understanding. And most importantly, there is hope.
If you or someone you know is affected by KS/CHH, reach out for support, speak to a specialist, and explore treatment options. Early diagnosis and tailored care make a life-changing difference.
