Q17. How is Kallmann syndrome diagnosed ?
Unless there is a family history of the condition Kallmann syndrome and CHH are not always easy to diagnose, even after the age of puberty has been reached. Peak age of diagnosis is between the late teenage years and early 20's, though it is possible to diagnose it earlier in some cases.
The lack of sense of smell, anosmia, is a characteristic of Kallmann syndrome and is the defining feature. There are other physical symptoms that can also occur in specific forms of Kallmann syndrome or CHH which can help point towards a diagnosis. While these features are not unique to Kallmann syndrome or CHH, their presence alongside absent puberty should alert doctors to the possibility of a diagnosis of Kallmann syndrome or CHH.
Possible physical features:
- Failure to start puberty at 14 for girls and 15 for boys (characterised by the start of menstrual bleeding in girls and testicular growth in boys.)
- Young, youthful appearance
- Lack of muscle development
- Tall stature - above average arm span and height
- Sparse pubic and axillary hair growth
- Anosmia - lack of sense of smell (Kallmann syndrome only)
- Cryptorchidism - one or both testes undescended at birth
- Nerve deafness
- Absence of one of the kidneys
- "Mirror" movements of the hands
- Cleft palette / hare lip or other mid line facial deformities
- Impacted teeth
Hormonal / biochemical features:
- Low levels of serum LH and FSH
- Low levels of serum oestrogen & progesterone or testosterone
- No sperm production
- Low level of Vitamin D
Medical Imaging tests:
- Hand / wrist x-ray to determine bone age
- MRI or CT scan to check the size & shape of the pituitary gland and to confirm the presence of the olfactory bulbs
- DEXA bone density scan to check for the strength of the bones.