Kallmann syndrome is a rare genetic disorder of endocrine system characterized by absence or delay in development of puberty together with loss of smell. In this disorder the development of sexual organs in both the genders is adversely affected. Untreated cases lead to infertility.
Kallmann syndrome is a type of hypogonadotropic hypogonadism. Due to deficient production of sex hormones there is delay or complete absence in development of secondary sexual characteristics. The hypothalamus situated in the brain fails to release gonadotropin releasing hormones. Kallmann syndrome is often diagnosed at puberty when the patient does not develop secondary sexual features such as pubic hair, menstruation, enlargement of breast, etc.
In males the features can be apparent during infancy such as undescended testes and small sized penis. Some of the symptoms may be different in males and females. The condition is caused by genetic abnormality. Treatment consists of hormonal replacement therapy.
What Causes Kallmann Syndrome?
Kallmann syndrome is a rare genetic syndrome first described by Franz Josef Kallaman in 1944. It is a congenital disorder caused due to defective gene. The genetic mutation occurs in certain genes called AL1, FGFR1, and PROKR2. These genes play a role in formation of cells in the brain which govern production of certain hormones that are required for sexual development.
Abnormality in the genes can interfere in development of sexual organs. Since the disorder is X-linked recessive, it can pass on from parents to children. The hypothalamus is a small part in the brain which secretes hormones to stimulate the pituitary gland to produce other hormones that control sexual features. However, the defect in the gene causes problem in production of these hormones resulting in reduced activity of testes in males and ovaries in females.
Signs And Symptoms Of Kallmann Syndrome
The symptoms of Kallmann syndrome are not life threatening. The main clinical feature of this syndrome is absence of puberty characteristics and loss of sense of smell. Since certain hormones dominate features in males and others in females, the symptoms may differ accordingly.
Males may present with these features:
- Undescended testes
- Small sized penis
- Decrease in libido
- Erectile dysfunction
- Loss of smell or diminished sense of smell.
- Loss of muscle mass.
- Absence or decrease of pubic hair.
In female patients:
- Stunted growth.
- Delayed or absence of menses.
- Absence of breast growth.
- Absence or decrease of pubic hair.
- Reduced lubrication of vagina.
- Loss of sense of smell.
There may be other associated symptoms which include:
- Cleft palate
- Cleft lips
- Absence of one kidney.
- Impairment in hearing.
- Dental deformities or missing teeth.
- Abnormality in movement of eyes.
- Abnormal eye movements.
Diagnosis And Treatment For Kallmann Syndrome
Clinician can diagnose the condition with prominent history of loss of smell and delayed features of puberty. Besides clinical examination, blood test for hormone level such as serum testosterone in males, serum estrogen and progesterone in females, LH and FSH hormone level in both will help to understand the disorder in a better way.
Genetic screening for detecting defective gene, X-ray for detecting fusion of epiphysis of bones, MRI scan of brain and smell test will help to diagnose Kallmann syndrome.
Kallmann syndrome treatment involves hormone replacement therapy. The aim of hormone therapy is to lift the level of sex hormones to a level where physical changes can occur at puberty. In males the therapy involves use of testosterone hormone. In females estrogen and progesterone are administered. If the woman wishes to conceive, she may need gonadotrophin hormone therapy to stimulate the follicles and produce mature eggs.
Unfortunately there is no treatment for reduced sense of smell. Patient must try to eat freshly prepared food as he may not be able to smell the food.