What happens in the body
Normal puberty is triggered from the hypothalamus: special neurons pulse gonadotropin-releasing hormone, which causes the pituitary gland to produce FSH and LH, which in turn stimulate the testes or ovaries. In Kallmann syndrome, these neurons do not reach the hypothalamus during fetal development because their path is associated with the formation of olfactory structures. As a result, the entire chain does not turn on: gonadotropins remain low, sex hormones are not produced, and the olfactory bulbs are underdeveloped or absent. Hence the characteristic combination of two seemingly unrelated characteristics.
- Disturbed migration of neurons during intrauterine development
- Low FSH and LH levels
- Low testosterone or estradiol
- Underdevelopment of the olfactory bulbs
- Inherited differently, random mutations also occur
- More often detected in men
How it manifests itself
In adolescence, boys' testicles and penis do not enlarge, facial and body hair does not grow, and their voice does not break. Growth may take longer than usual because growth plates close later, causing body proportions to become elongated. Girls do not begin to grow mammary glands and do not menstruate. Common symptoms are decreased libido, fatigue, and in adult men, decreased muscle mass. The lack of smell often goes unnoticed: a person has not known any other condition since childhood and does not complain until he is specifically asked.
- Absence or arrest of puberty
- Small testicular volume in men
- Lack of menstruation in women
- Decreased or absent sense of smell
- Elongated body proportions
- Decreased libido and fatigue
- Decreased bone density in adults
Related Features
Some patients have additional signs that help to suspect this particular syndrome. Among them are a cleft lip or palate, hearing impairment, the absence of one kidney, dental anomalies, short fingers, and also a feature in which a person cannot move his hands separately and repeats the movement of one hand with the other. Not all patients have these features, and their absence does not exclude the diagnosis. However, during the examination, the doctor purposefully asks about them and prescribes an ultrasound of the kidneys and a hearing test.
- Cleft lip or palate
- Hearing loss
- Absence of one kidney
- Anomalies of dental development
- Mirror hand movements
- Eye development disorders in rare cases
Survey
They start with a blood test for FSH, LH and sex hormones: a characteristic combination is low gonadotropins with low testosterone or estradiol. Additionally, prolactin, thyroid hormones and cortisol are checked to rule out other causes. MRI of the brain and pituitary gland allows you to see the underdevelopment of the olfactory structures and exclude a tumor. The sense of smell must be examined with special sets of odors, since the patient himself is often not aware of the problem. Karyotyping and genetic tests clarify the shape, and a spermogram in men assesses the initial state of fertility.
- FSH, LH, testosterone or estradiol
- Prolactin, thyroid hormones, cortisol
- MRI of the brain and pituitary gland
- Olfactory research
- Karyotyping and genetic tests
- Densitometry to assess bone density
- Ultrasound of the pelvic organs or scrotum
Treatment
The treatment is prescribed by an endocrinologist, and it solves two problems. The first is to ensure the development of secondary sexual characteristics and normal hormone levels: for this, sex hormone replacement therapy is used, which begins in adolescence with a gradual increase in dose so that maturation proceeds at a natural pace. It also protects bones from loss of density. The second problem arises when planning children: conventional replacement therapy does not restore sperm production or egg maturation, therefore special stimulating regimens with gonadotropins are used. The sense of smell cannot be treated, but a person adapts; It is important to install smoke detectors at home and monitor the expiration dates of products.
- Sex hormone replacement therapy
- Gradual increase in dose during adolescence
- Bone Density Control
- Gonadotropin stimulating therapy when planning children
- Observation by an andrologist or gynecologist
- Family genetic counseling
- Household measures in the absence of smell: smoke detectors, food control
